diff --git a/database/exip.sql b/database/exip.sql
index 91105f45a0..f3bf695d05 100644
--- a/database/exip.sql
+++ b/database/exip.sql
@@ -646,9 +646,9 @@ DROP TABLE IF EXISTS `DeclarationModernSlaveryVersion`;
 CREATE TABLE `DeclarationModernSlaveryVersion` (
   `id` varchar(191) COLLATE utf8mb4_unicode_ci NOT NULL,
   `declarationModernSlavery` varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
-  `hasNoOffensesOrInvestigations` varchar(3) COLLATE utf8mb4_unicode_ci NOT NULL DEFAULT '',
-  `isNotAwareOfExistingSlavery` varchar(3) COLLATE utf8mb4_unicode_ci NOT NULL DEFAULT '',
-  `willAdhereToAllRequirements` varchar(3) COLLATE utf8mb4_unicode_ci NOT NULL DEFAULT '',
+  `hasNoOffensesOrInvestigations` tinyint(1) DEFAULT NULL,
+  `isNotAwareOfExistingSlavery` tinyint(1) DEFAULT NULL,
+  `willAdhereToAllRequirements` tinyint(1) DEFAULT NULL,
   PRIMARY KEY (`id`),
   KEY `DeclarationModernSlaveryVersion_declarationModernSlavery_idx` (`declarationModernSlavery`),
   CONSTRAINT `DeclarationModernSlaveryVersion_declarationModernSlavery_fkey` FOREIGN KEY (`declarationModernSlavery`) REFERENCES `DeclarationModernSlavery` (`id`) ON DELETE
diff --git a/src/api/data-migration/version-1-to-version-2/create-cuid/index.ts b/src/api/data-migration/helpers/create-cuid/index.ts
similarity index 100%
rename from src/api/data-migration/version-1-to-version-2/create-cuid/index.ts
rename to src/api/data-migration/helpers/create-cuid/index.ts
diff --git a/src/api/data-migration/helpers/get-all-declaration-modern-slaveries.ts b/src/api/data-migration/helpers/get-all-declaration-modern-slaveries.ts
new file mode 100644
index 0000000000..fc09af4d24
--- /dev/null
+++ b/src/api/data-migration/helpers/get-all-declaration-modern-slaveries.ts
@@ -0,0 +1,27 @@
+import { Connection } from 'mysql2/promise';
+import executeSqlQuery from '../execute-sql-query';
+import { ApplicationDeclarationModernSlavery } from '../../types';
+
+/**
+ * getAllDeclarationModernSlaveries
+ * Get all entries in the "DeclarationModernSlavery" table
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<ApplicationDeclarationModernSlavery>>}
+ */
+const getAllDeclarationModernSlaveries = async (connection: Connection) => {
+  const loggingMessage = 'Getting all declaration modern slaveries';
+
+  try {
+    const query = 'SELECT * FROM DeclarationModernSlavery';
+
+    const [declarations] = await executeSqlQuery({ connection, query, loggingMessage });
+
+    return declarations as Array<ApplicationDeclarationModernSlavery>;
+  } catch (error) {
+    console.error('🚨 Error %s %o', loggingMessage, error);
+
+    throw new Error(`🚨 error ${loggingMessage} ${error}`);
+  }
+};
+
+export default getAllDeclarationModernSlaveries;
diff --git a/src/api/data-migration/helpers/get-all-declarations.ts b/src/api/data-migration/helpers/get-all-declarations.ts
new file mode 100644
index 0000000000..9c8ae0d648
--- /dev/null
+++ b/src/api/data-migration/helpers/get-all-declarations.ts
@@ -0,0 +1,27 @@
+import { Connection } from 'mysql2/promise';
+import executeSqlQuery from '../execute-sql-query';
+import { ApplicationDeclaration } from '../../types';
+
+/**
+ * getAllDeclarations
+ * Get all entries in the "Declaration" table
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<ApplicationDeclaration>>}
+ */
+const getAllDeclarations = async (connection: Connection) => {
+  const loggingMessage = 'Getting all declarations';
+
+  try {
+    const query = 'SELECT * FROM Application';
+
+    const [declarations] = await executeSqlQuery({ connection, query, loggingMessage });
+
+    return declarations as Array<ApplicationDeclaration>;
+  } catch (error) {
+    console.error('🚨 Error %s %o', loggingMessage, error);
+
+    throw new Error(`🚨 error ${loggingMessage} ${error}`);
+  }
+};
+
+export default getAllDeclarations;
diff --git a/src/api/data-migration/version-1-to-version-2/get-all-non-submitted-applications.ts b/src/api/data-migration/helpers/get-all-non-submitted-applications.ts
similarity index 93%
rename from src/api/data-migration/version-1-to-version-2/get-all-non-submitted-applications.ts
rename to src/api/data-migration/helpers/get-all-non-submitted-applications.ts
index d2e72fc803..035b02e8b8 100644
--- a/src/api/data-migration/version-1-to-version-2/get-all-non-submitted-applications.ts
+++ b/src/api/data-migration/helpers/get-all-non-submitted-applications.ts
@@ -9,7 +9,7 @@ const { STATUS } = APPLICATION;
  * getAllNonSubmittedApplications
  * Get all entries in the "Application" table that do NOT have a SUBMITTED status
  * @param {Connection} connection: SQL database connection
- * @returns {Promise<Application>} Non-submitted applications
+ * @returns {Promise<Array<Application>>} Non-submitted applications
  */
 const getAllNonSubmittedApplications = async (connection: Connection) => {
   const loggingMessage = 'Getting all non-submitted applications';
diff --git a/src/api/data-migration/version-1-to-version-2/get-all-submitted-applications.ts b/src/api/data-migration/helpers/get-all-submitted-applications.ts
similarity index 93%
rename from src/api/data-migration/version-1-to-version-2/get-all-submitted-applications.ts
rename to src/api/data-migration/helpers/get-all-submitted-applications.ts
index 7c1dddcc93..e7efde6495 100644
--- a/src/api/data-migration/version-1-to-version-2/get-all-submitted-applications.ts
+++ b/src/api/data-migration/helpers/get-all-submitted-applications.ts
@@ -9,7 +9,7 @@ const { STATUS } = APPLICATION;
  * getAllSubmittedApplications
  * Get all entries in the "Application" table with a SUBMITTED status
  * @param {Connection} connection: SQL database connection
- * @returns {Promise<Application>} Submitted applications
+ * @returns {Promise<Array<Application>>} Submitted applications
  */
 const getAllSubmittedApplications = async (connection: Connection) => {
   const loggingMessage = 'Getting all submitted applications';
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/create-company-different-trading-address.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/create-company-different-trading-address.ts
index 2fd6949f7d..7f87bc19b3 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/create-company-different-trading-address.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/create-company-different-trading-address.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import createCuid from '../create-cuid';
+import createCuid from '../../helpers/create-cuid';
 import executeSqlQuery from '../../execute-sql-query';
 import { Application } from '../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/declaration-version-relationship/non-submitted-applications.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/declaration-version-relationship/non-submitted-applications.ts
index c2c6c9c935..3c1977097a 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/declaration-version-relationship/non-submitted-applications.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/declaration-version-relationship/non-submitted-applications.ts
@@ -1,7 +1,7 @@
 import { Connection } from 'mysql2/promise';
 import { DECLARATIONS } from '../../../../constants';
-import getAllNonSubmittedApplications from '../../get-all-non-submitted-applications';
-import createCuid from '../../create-cuid';
+import getAllNonSubmittedApplications from '../../../helpers/get-all-non-submitted-applications';
+import createCuid from '../../../helpers/create-cuid';
 import executeSqlQuery from '../../../execute-sql-query';
 import { Application } from '../../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/declaration-version-relationship/submitted-applications.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/declaration-version-relationship/submitted-applications.ts
index e3d574c6ff..b6fbad8ff8 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/declaration-version-relationship/submitted-applications.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/declaration-version-relationship/submitted-applications.ts
@@ -1,7 +1,7 @@
 import { Connection } from 'mysql2/promise';
 import { DECLARATIONS } from '../../../../constants';
-import getAllSubmittedApplications from '../../get-all-submitted-applications';
-import createCuid from '../../create-cuid';
+import getAllSubmittedApplications from '../../../helpers/get-all-submitted-applications';
+import createCuid from '../../../helpers/create-cuid';
 import executeSqlQuery from '../../../execute-sql-query';
 import { Application } from '../../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/export-contract-agent/create-agent-service-charges.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/export-contract-agent/create-agent-service-charges.ts
index 68756c31df..1caae17be2 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/export-contract-agent/create-agent-service-charges.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/export-contract-agent/create-agent-service-charges.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import createCuid from '../../create-cuid';
+import createCuid from '../../../helpers/create-cuid';
 import executeSqlQuery from '../../../execute-sql-query';
 import { Application } from '../../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/export-contract-agent/create-agent-services.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/export-contract-agent/create-agent-services.ts
index ed6857a788..d9c2f8de18 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/export-contract-agent/create-agent-services.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/export-contract-agent/create-agent-services.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import createCuid from '../../create-cuid';
+import createCuid from '../../../helpers/create-cuid';
 import executeSqlQuery from '../../../execute-sql-query';
 import { Application } from '../../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/export-contract-agent/create-initial-agents.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/export-contract-agent/create-initial-agents.ts
index a07af72e67..a48ee415fd 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/export-contract-agent/create-initial-agents.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/export-contract-agent/create-initial-agents.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import createCuid from '../../create-cuid';
+import createCuid from '../../../helpers/create-cuid';
 import executeSqlQuery from '../../../execute-sql-query';
 import { Application } from '../../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/jointly-insured-party.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/jointly-insured-party.ts
index 959362d4a3..a8b99329f2 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/jointly-insured-party.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/jointly-insured-party.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import createCuid from '../create-cuid';
+import createCuid from '../../helpers/create-cuid';
 import executeSqlQuery from '../../execute-sql-query';
 import { Application } from '../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-initial-loss-payees.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-initial-loss-payees.ts
index e1e3924d6d..01136c23d5 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-initial-loss-payees.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-initial-loss-payees.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import createCuid from '../../create-cuid';
+import createCuid from '../../../helpers/create-cuid';
 import executeSqlQuery from '../../../execute-sql-query';
 import { Application } from '../../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-international-vector.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-international-vector.ts
index 9aac8af0b3..954a136ae1 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-international-vector.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-international-vector.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import createCuid from '../../create-cuid';
+import createCuid from '../../../helpers/create-cuid';
 import executeSqlQuery from '../../../execute-sql-query';
 import { Application } from '../../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-international.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-international.ts
index 90727b0580..2eec303f4c 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-international.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-international.ts
@@ -1,6 +1,6 @@
 import { Connection } from 'mysql2/promise';
 import getAllLossPayees from '../../get-all-loss-payees';
-import createCuid from '../../create-cuid';
+import createCuid from '../../../helpers/create-cuid';
 import executeSqlQuery from '../../../execute-sql-query';
 
 /**
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-uk-vector.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-uk-vector.ts
index 35387f2dcd..559bd6fe7f 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-uk-vector.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-uk-vector.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import createCuid from '../../create-cuid';
+import createCuid from '../../../helpers/create-cuid';
 import executeSqlQuery from '../../../execute-sql-query';
 import { Application } from '../../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-uk.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-uk.ts
index 54ea6a7be8..9bcc926565 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-uk.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/loss-payee/create-loss-payee-financial-uk.ts
@@ -1,6 +1,6 @@
 import { Connection } from 'mysql2/promise';
 import getAllLossPayees from '../../get-all-loss-payees';
-import createCuid from '../../create-cuid';
+import createCuid from '../../../helpers/create-cuid';
 import executeSqlQuery from '../../../execute-sql-query';
 
 /**
diff --git a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/private-market.ts b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/private-market.ts
index adc6306927..f806b18436 100644
--- a/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/private-market.ts
+++ b/src/api/data-migration/version-1-to-version-2/create-new-application-relationships/private-market.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import createCuid from '../create-cuid';
+import createCuid from '../../helpers/create-cuid';
 import executeSqlQuery from '../../execute-sql-query';
 import { Application } from '../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/update-applications/move-buyer-contact-fields.ts b/src/api/data-migration/version-1-to-version-2/update-applications/move-buyer-contact-fields.ts
index d526ee1dd8..e95a20b2db 100644
--- a/src/api/data-migration/version-1-to-version-2/update-applications/move-buyer-contact-fields.ts
+++ b/src/api/data-migration/version-1-to-version-2/update-applications/move-buyer-contact-fields.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import createCuid from '../create-cuid';
+import createCuid from '../../helpers/create-cuid';
 import executeSqlQuery from '../../execute-sql-query';
 import { ApplicationBuyerMvp } from '../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/update-applications/move-buyer-relationship-fields.ts b/src/api/data-migration/version-1-to-version-2/update-applications/move-buyer-relationship-fields.ts
index a4b926cc6e..4ce7d74215 100644
--- a/src/api/data-migration/version-1-to-version-2/update-applications/move-buyer-relationship-fields.ts
+++ b/src/api/data-migration/version-1-to-version-2/update-applications/move-buyer-relationship-fields.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import createCuid from '../create-cuid';
+import createCuid from '../../helpers/create-cuid';
 import executeSqlQuery from '../../execute-sql-query';
 import { ApplicationBuyerMvp } from '../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/update-applications/move-buyer-trading-history-fields.ts b/src/api/data-migration/version-1-to-version-2/update-applications/move-buyer-trading-history-fields.ts
index ff0bf90717..01c4942906 100644
--- a/src/api/data-migration/version-1-to-version-2/update-applications/move-buyer-trading-history-fields.ts
+++ b/src/api/data-migration/version-1-to-version-2/update-applications/move-buyer-trading-history-fields.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import createCuid from '../create-cuid';
+import createCuid from '../../helpers/create-cuid';
 import executeSqlQuery from '../../execute-sql-query';
 import { ApplicationBuyerMvp } from '../../../types';
 
diff --git a/src/api/data-migration/version-1-to-version-2/update-applications/update-declaration-fields.ts b/src/api/data-migration/version-1-to-version-2/update-applications/update-declaration-fields.ts
index 6cb8b5c644..6563f9cde0 100644
--- a/src/api/data-migration/version-1-to-version-2/update-applications/update-declaration-fields.ts
+++ b/src/api/data-migration/version-1-to-version-2/update-applications/update-declaration-fields.ts
@@ -1,5 +1,5 @@
 import { Connection } from 'mysql2/promise';
-import getAllNonSubmittedApplications from '../get-all-non-submitted-applications';
+import getAllNonSubmittedApplications from '../../helpers/get-all-non-submitted-applications';
 import executeSqlQuery from '../../execute-sql-query';
 import { Application } from '../../../types';
 
diff --git a/src/api/data-migration/version-2-to-version-3/index.ts b/src/api/data-migration/version-2-to-version-3/index.ts
index 6b0942f349..60680e59b2 100644
--- a/src/api/data-migration/version-2-to-version-3/index.ts
+++ b/src/api/data-migration/version-2-to-version-3/index.ts
@@ -3,8 +3,8 @@ import updateApplications from './update-applications';
 
 /**
  * dataMigration
- * Update all accounts and applications from the MVP data model/structure,
- * to the new "No PDF" data model/structure.
+ * Update all applications from the V2 data model/structure,
+ * to the V3 data model/structure.
  * @returns {Function} process.exit()
  */
 const dataMigration = async () => {
diff --git a/src/api/data-migration/version-2-to-version-3/update-applications/index.ts b/src/api/data-migration/version-2-to-version-3/update-applications/index.ts
index cd207a1fd2..6753529f72 100644
--- a/src/api/data-migration/version-2-to-version-3/update-applications/index.ts
+++ b/src/api/data-migration/version-2-to-version-3/update-applications/index.ts
@@ -7,7 +7,7 @@ import updateApplicationMigrated from './update-application-migrated';
 
 /**
  * updateApplications
- * Update applications from the "No PDF" data model/structure, to the new "No PDF iterations" data model/structure.
+ * Update applications from the V2 data model/structure, to the V3 data model/structure.
  * @param {Connection} connection: SQL database connection
  * @returns {Promise<Array<object>>} executeSqlQuery responses
  */
diff --git a/src/api/data-migration/version-3-to-version-4/README.md b/src/api/data-migration/version-3-to-version-4/README.md
new file mode 100644
index 0000000000..6d98c954e6
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/README.md
@@ -0,0 +1,58 @@
+# EXIP API - data migration - version 2 to version 3 :file_folder:
+
+This directory contains source code for migrating version 2 of EXIP data into the version 3 data structure.
+
+- Version 1 is MVP. This is the first release with account and application functionalities.
+- Version 2 is "No PDF". This is a large iteration of MVP, where we allow more applications through and collect more information, depending on answers a user provides.
+- Version 3 is a small iteration of "No PDF". This is mostly design and content improvements, however 1x field has been added to the database.
+
+## In version 3, the following data has been added
+
+- `Policy` table - 1x new field - `requestedCreditLimit`.
+
+## Prerequisites :gear:
+
+To set up and run the API locally to test this data migration, you'll need the following prerequisites:
+
+- Node.js version 16.17.0 or higher along with the corresponding `npm` package manager.
+- A MySQL database with the version 2 (No PDF) data structure.
+- An operational API (parent directory - see the API's README).
+- The `DATABASE_URL` environment variable should be configured to point to your local MySQL database, for example: `mysql://root:@localhost:1234/db-name`.
+- The local `DATABASE_USER` environment variable
+- The local `DATABASE_PASSWORD` environment variable
+- The local `CUID_FINGERPRINT` environment variable
+- `mysql2` NPM package installed as an API dependency.
+- `ts-node` NPM package installed locally.
+
+## Running Locally :computer:
+
+1. Ensure that your database has the version 2 (No PDF) data structure.
+2. In the API directory, execute `npm run data-migration`.
+
+The migration should successfully do the following:
+
+1. Connect to the database.
+2. Remove the application `migratedV1toV2` field.
+3. Create a new application `migratedV2toV3` field.
+4. Create a new requestedCreditLimit field in the policy table.
+5. Update the application version number.
+6. Update the new application `migratedV2toV3` field.
+
+## How to ensure that data migration was successful
+
+1. All applications should be aligned with the version 3 data model (listed above)
+2. In the UI, all existing applications with a status of "in progress" can be progressed and successfully submitted.
+
+## What happens to applications that are in progress :microscope:
+
+Due to the nature of GraphQL and KeystoneJS - the version 2 and version 3 data models are essentially "out of sync".
+
+If we try to run the version 3 API, with version 2 data, things will not work.
+
+Similarly, if we migrate the database and the API is running on version 3 - any applications created with the version 2 data model need to be migrated to the new version 3 model - hence why we need migration logic.
+
+This means that if a user has completed e.g all questions in an application, but has not yet submitted - and then we migrate to version 3, the user's application will be migrated from version 2 ("No PDF") to version 3 ("No PDF iterations"). Because this migration is minimal, only one section will be marked as incomplete - the "Policy" section. Because the `requestedCreditLimit` field is now required as part of version 3 ("No PDF interations).
+
+This is an intentional behaviour, so that a user can continue to complete and submit an application. The alternative to this is to ask a user to start again, which is not recommended.
+
+If you have any specific questions or need further guidance related to this data migration or the API, please feel free to ask.
diff --git a/src/api/data-migration/version-3-to-version-4/index.ts b/src/api/data-migration/version-3-to-version-4/index.ts
new file mode 100644
index 0000000000..cee97c5f77
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/index.ts
@@ -0,0 +1,30 @@
+import connectToDatabase from '../connect-to-database';
+import updateApplications from './update-applications';
+
+/**
+ * dataMigration
+ * Update all applications from the V3 data model/structure,
+ * to the V4 data model/structure.
+ * @returns {Function} process.exit()
+ */
+const dataMigration = async () => {
+  try {
+    console.info('🚀 Beginning data migration (v3 to v4)');
+
+    const connection = await connectToDatabase();
+
+    await updateApplications(connection);
+
+    console.info('✅ Applications successfully updated');
+
+    console.info('🎉 Migration complete. Exiting script');
+
+    process.exit();
+  } catch (error) {
+    console.error('🚨 Error with data migration %o', error);
+
+    throw new Error(`🚨 Error with data migration ${error}`);
+  }
+};
+
+dataMigration();
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/add-application-migrated-v3-to-v4-field.ts b/src/api/data-migration/version-3-to-version-4/update-applications/add-application-migrated-v3-to-v4-field.ts
new file mode 100644
index 0000000000..3b30e0603b
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/add-application-migrated-v3-to-v4-field.ts
@@ -0,0 +1,18 @@
+import { Connection } from 'mysql2/promise';
+import executeSqlQuery from '../../execute-sql-query';
+
+/**
+ * addMigratedV3toV4Field
+ * Add a migratedV3toV4 field to the application table.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const addMigratedV3toV4Field = (connection: Connection) => {
+  const loggingMessage = 'Adding FIELD migratedV3toV4 to application table';
+
+  const query = `ALTER TABLE Application ADD migratedV3toV4 tinyint(1) DEFAULT NULL`;
+
+  return executeSqlQuery({ connection, query, loggingMessage });
+};
+
+export default addMigratedV3toV4Field;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/create-declaration-modern-slavery-table.ts b/src/api/data-migration/version-3-to-version-4/update-applications/create-declaration-modern-slavery-table.ts
new file mode 100644
index 0000000000..ed8da8bcd0
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/create-declaration-modern-slavery-table.ts
@@ -0,0 +1,28 @@
+import { Connection } from 'mysql2/promise';
+import executeSqlQuery from '../../execute-sql-query';
+
+/**
+ * createDeclarationModernSlaveryTable
+ * Create new "declaration modern slavery" database table.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const createDeclarationModernSlaveryTable = (connection: Connection) => {
+  const loggingMessage = 'Creating TABLE - declaration modern slavery';
+
+  const query = `
+    CREATE TABLE DeclarationModernSlavery (
+      id varchar(191) COLLATE utf8mb4_unicode_ci NOT NULL,
+      declaration varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
+      version varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
+      willAdhereToAllRequirements tinyint(1) DEFAULT NULL,
+      hasNoOffensesOrInvestigations tinyint(1) DEFAULT NULL,
+      isNotAwareOfExistingSlavery tinyint(1) DEFAULT NULL,
+      PRIMARY KEY (id)
+    ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_unicode_ci;
+  `;
+
+  return executeSqlQuery({ connection, query, loggingMessage });
+};
+
+export default createDeclarationModernSlaveryTable;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/create-declaration-modern-slavery-version-table.ts b/src/api/data-migration/version-3-to-version-4/update-applications/create-declaration-modern-slavery-version-table.ts
new file mode 100644
index 0000000000..7c834bc499
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/create-declaration-modern-slavery-version-table.ts
@@ -0,0 +1,27 @@
+import { Connection } from 'mysql2/promise';
+import executeSqlQuery from '../../execute-sql-query';
+
+/**
+ * createDeclarationModernSlaveryVersionTable
+ * Create new "declaration modern slavery version" database table.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const createDeclarationModernSlaveryVersionTable = (connection: Connection) => {
+  const loggingMessage = 'Creating TABLE - declaration modern slavery version';
+
+  const query = `
+    CREATE TABLE DeclarationModernSlaveryVersion (
+      id varchar(191) COLLATE utf8mb4_unicode_ci NOT NULL,
+      declarationModernSlavery varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
+      hasNoOffensesOrInvestigations tinyint(1) DEFAULT NULL,
+      isNotAwareOfExistingSlavery tinyint(1) DEFAULT NULL,
+      willAdhereToAllRequirements tinyint(1) DEFAULT NULL,
+      PRIMARY KEY (id)
+    ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_unicode_ci;
+  `;
+
+  return executeSqlQuery({ connection, query, loggingMessage });
+};
+
+export default createDeclarationModernSlaveryVersionTable;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/index.ts b/src/api/data-migration/version-3-to-version-4/update-applications/index.ts
new file mode 100644
index 0000000000..705af38cd1
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/index.ts
@@ -0,0 +1,41 @@
+import { Connection } from 'mysql2/promise';
+import removeMigratedV2toV3Field from './remove-application-migrated-v2-to-v3-field';
+import addMigratedV3toV4Field from './add-application-migrated-v3-to-v4-field';
+import createDeclarationModernSlaveryTable from './create-declaration-modern-slavery-table';
+import createDeclarationModernSlaveryVersionTable from './create-declaration-modern-slavery-version-table';
+import updateDeclarations from './update-declarations';
+import updateApplicationMigrated from './update-application-migrated';
+
+/**
+ * updateApplications
+ * Update applications from the V3 data model/structure, to the V4 data model/structure.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery responses
+ */
+const updateApplications = async (connection: Connection) => {
+  const loggingMessage = 'Updating applications';
+
+  console.info('✅ %s', loggingMessage);
+
+  try {
+    const promises = await Promise.all([
+      removeMigratedV2toV3Field(connection),
+      addMigratedV3toV4Field(connection),
+
+      createDeclarationModernSlaveryTable(connection),
+      createDeclarationModernSlaveryVersionTable(connection),
+
+      updateDeclarations(connection),
+
+      updateApplicationMigrated(connection),
+    ]);
+
+    return promises;
+  } catch (error) {
+    console.error('🚨 Error %s %o', loggingMessage, error);
+
+    throw new Error(`🚨 error ${loggingMessage} ${error}`);
+  }
+};
+
+export default updateApplications;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/remove-application-migrated-v2-to-v3-field.ts b/src/api/data-migration/version-3-to-version-4/update-applications/remove-application-migrated-v2-to-v3-field.ts
new file mode 100644
index 0000000000..fc6b565330
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/remove-application-migrated-v2-to-v3-field.ts
@@ -0,0 +1,20 @@
+import { Connection } from 'mysql2/promise';
+import executeSqlQuery from '../../execute-sql-query';
+
+/**
+ * removeMigratedV2toV3Field
+ * Remove the migratedV2toV3 field from the application table.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const removeMigratedV2toV3Field = (connection: Connection) => {
+  const loggingMessage = 'Removing FIELD migratedV2toV3 from application table';
+
+  const query = `
+    ALTER TABLE Application DROP COLUMN migratedV2toV3
+  `;
+
+  return executeSqlQuery({ connection, query, loggingMessage });
+};
+
+export default removeMigratedV2toV3Field;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/update-application-migrated.ts b/src/api/data-migration/version-3-to-version-4/update-applications/update-application-migrated.ts
new file mode 100644
index 0000000000..650304221e
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/update-application-migrated.ts
@@ -0,0 +1,23 @@
+import { Connection } from 'mysql2/promise';
+import { APPLICATION } from '../../../constants';
+import executeSqlQuery from '../../execute-sql-query';
+
+const { STATUS } = APPLICATION;
+
+/**
+ * updateApplicationMigrated
+ * Update IN_PROGRESS applications migratedV3toV4 fields to have a value of 1/true
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const updateApplicationMigrated = (connection: Connection) => {
+  const loggingMessage = `Updating migratedV3toV4 FIELD to true in the application table`;
+
+  const query = `
+    UPDATE Application SET migratedV3toV4 = 1 WHERE status = '${STATUS.IN_PROGRESS}'
+  `;
+
+  return executeSqlQuery({ connection, query, loggingMessage });
+};
+
+export default updateApplicationMigrated;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/update-application-version.ts b/src/api/data-migration/version-3-to-version-4/update-applications/update-application-version.ts
new file mode 100644
index 0000000000..8650ce72fb
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/update-application-version.ts
@@ -0,0 +1,25 @@
+import { Connection } from 'mysql2/promise';
+import { APPLICATION } from '../../../constants';
+import executeSqlQuery from '../../execute-sql-query';
+
+const { STATUS, LATEST_VERSION_NUMBER, VERSIONS } = APPLICATION;
+
+/**
+ * updateApplicationVersion
+ * Update IN_PROGRESS applications from the No PDF version (2), to the new "No PDF iterations" version (3)
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const updateApplicationVersion = (connection: Connection) => {
+  const originalVersionNumber = VERSIONS[1].VERSION_NUMBER;
+
+  const loggingMessage = `Updating IN_PROGRESS FIELD VERSION from ${originalVersionNumber} to ${LATEST_VERSION_NUMBER} in the application table`;
+
+  const query = `
+    UPDATE Application SET version = '${LATEST_VERSION_NUMBER}' WHERE status = '${STATUS.IN_PROGRESS}'
+  `;
+
+  return executeSqlQuery({ connection, query, loggingMessage });
+};
+
+export default updateApplicationVersion;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-constraints.ts b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-constraints.ts
new file mode 100644
index 0000000000..d2c34e3558
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-constraints.ts
@@ -0,0 +1,34 @@
+import { Connection } from 'mysql2/promise';
+import executeSqlQuery from '../../../execute-sql-query';
+
+/**
+ * addDeclarationModernSlaveryConstraints
+ * - Add a modernSlavery constraint to the Declaration table.
+ * - Add a declaration constraint to the DeclarationModernSlavery table.
+ * - Add a version constraint to the DeclarationModernSlavery table.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const addDeclarationModernSlaveryConstraints = async (connection: Connection) => {
+  const queries = await Promise.all([
+    executeSqlQuery({
+      connection,
+      query: `ALTER TABLE Declaration ADD CONSTRAINT Declaration_modernSlavery_fkey FOREIGN KEY (modernSlavery) REFERENCES DeclarationModernSlavery (id) ON DELETE SET NULL ON UPDATE CASCADE`,
+      loggingMessage: 'Adding CONSTRAINT modernSlavery to Declaration table',
+    }),
+    executeSqlQuery({
+      connection,
+      query: `ALTER TABLE DeclarationModernSlavery ADD CONSTRAINT DeclarationModernSlavery_declaration_fkey FOREIGN KEY (declaration) REFERENCES Declaration (id) ON DELETE SET NULL ON UPDATE CASCADE`,
+      loggingMessage: 'Adding CONSTRAINT declaration to DeclarationModernSlavery table',
+    }),
+    executeSqlQuery({
+      connection,
+      query: `ALTER TABLE DeclarationModernSlavery ADD CONSTRAINT DeclarationModernSlavery_version_fkey FOREIGN KEY (version) REFERENCES DeclarationModernSlavery (id) ON DELETE SET NULL ON UPDATE CASCADE`,
+      loggingMessage: 'Adding CONSTRAINT version to DeclarationModernSlavery table',
+    }),
+  ]);
+
+  return queries;
+};
+
+export default addDeclarationModernSlaveryConstraints;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-field.ts b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-field.ts
new file mode 100644
index 0000000000..8805341f59
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-field.ts
@@ -0,0 +1,20 @@
+import { Connection } from 'mysql2/promise';
+import executeSqlQuery from '../../../execute-sql-query';
+
+/**
+ * addDeclarationModernSlaveryField
+ * Add a modernSlavery field to the declaration table.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const addDeclarationModernSlaveryField = (connection: Connection) => {
+  const loggingMessage = 'Adding FIELD modernSlavery to declaration table';
+
+  const query = `
+    ALTER TABLE Declaration ADD modernSlavery varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL
+  `;
+
+  return executeSqlQuery({ connection, query, loggingMessage });
+};
+
+export default addDeclarationModernSlaveryField;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-keys.ts b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-keys.ts
new file mode 100644
index 0000000000..08028e79d0
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-keys.ts
@@ -0,0 +1,27 @@
+import { Connection } from 'mysql2/promise';
+import executeSqlQuery from '../../../execute-sql-query';
+
+/**
+ * addDeclarationModernSlaveryKeys
+ * Add declaration and version keys to the DeclarationModernSlavery table.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const addDeclarationModernSlaveryKeys = async (connection: Connection) => {
+  const queries = await Promise.all([
+    executeSqlQuery({
+      connection,
+      query: 'ALTER TABLE DeclarationModernSlavery ADD KEY DeclarationModernSlavery_declaration_idx(declaration)',
+      loggingMessage: 'Adding KEY declaration to DeclarationModernSlavery table',
+    }),
+    executeSqlQuery({
+      connection,
+      query: 'ALTER TABLE DeclarationModernSlavery ADD KEY DeclarationModernSlavery_version_idx(version)',
+      loggingMessage: 'Adding KEY version to DeclarationModernSlavery table',
+    }),
+  ]);
+
+  return queries;
+};
+
+export default addDeclarationModernSlaveryKeys;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-version-constraint.ts b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-version-constraint.ts
new file mode 100644
index 0000000000..a170117bdb
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-version-constraint.ts
@@ -0,0 +1,17 @@
+import { Connection } from 'mysql2/promise';
+import executeSqlQuery from '../../../execute-sql-query';
+
+/**
+ * addDeclarationModernSlaveryVersionConstraint
+ * Add a declarationModernSlavery constraint to the DeclarationModernSlaveryVersion table.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const addDeclarationModernSlaveryVersionConstraint = async (connection: Connection) =>
+  executeSqlQuery({
+    connection,
+    query: `ALTER TABLE DeclarationModernSlaveryVersion ADD CONSTRAINT DeclarationModernSlaveryVersion_declarationModernSlavery_fkey FOREIGN KEY (declarationModernSlavery) REFERENCES DeclarationModernSlavery (id) ON DELETE SET NULL ON UPDATE CASCADE`,
+    loggingMessage: 'Adding CONSTRAINT declarationModernSlavery to DeclarationModernSlaveryVersion table',
+  });
+
+export default addDeclarationModernSlaveryVersionConstraint;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-version-key.ts b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-version-key.ts
new file mode 100644
index 0000000000..d7c972170f
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/add-declaration-modern-slavery-version-key.ts
@@ -0,0 +1,17 @@
+import { Connection } from 'mysql2/promise';
+import executeSqlQuery from '../../../execute-sql-query';
+
+/**
+ * addDeclarationModernSlaveryVersionKey
+ * Add a declarationModernSlavery key to the DeclarationModernSlaveryVersion table.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const addDeclarationModernSlaveryVersionKey = async (connection: Connection) =>
+  executeSqlQuery({
+    connection,
+    query: 'ALTER TABLE DeclarationModernSlaveryVersion ADD KEY DeclarationModernSlaveryVersion_declarationModernSlavery_idx(declarationModernSlavery)',
+    loggingMessage: 'Adding KEY declarationModernSlavery to DeclarationModernSlaveryVersion table',
+  });
+
+export default addDeclarationModernSlaveryVersionKey;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/create-declaration-modern-slavery-rows.ts b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/create-declaration-modern-slavery-rows.ts
new file mode 100644
index 0000000000..1c1c18b4ac
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/create-declaration-modern-slavery-rows.ts
@@ -0,0 +1,33 @@
+import { Connection } from 'mysql2/promise';
+import getAllDeclarations from '../../../helpers/get-all-declarations';
+import createCuid from '../../../helpers/create-cuid';
+import executeSqlQuery from '../../../execute-sql-query';
+import { ApplicationDeclaration } from '../../../../types';
+
+/**
+ * createDeclarationModernSlaveryRows
+ * For each declaration, create a new row in the DeclarationModernSlavery table.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const createDeclarationModernSlaveryRows = async (connection: Connection) => {
+  const declarations = await getAllDeclarations(connection);
+
+  const declarationModernSlaveryPromises = declarations.map(async (declaration: ApplicationDeclaration) => {
+    const { id: declarationId } = declaration;
+
+    const theValues = `('${createCuid()}', '${declarationId}')`;
+
+    const query = await executeSqlQuery({
+      connection,
+      query: `INSERT INTO DeclarationModernSlavery (id, declaration) VALUES ${theValues}`,
+      loggingMessage: `Creating DeclarationModernSlavery entry for declaration ${declarationId}`,
+    });
+
+    return query;
+  });
+
+  return Promise.all(declarationModernSlaveryPromises);
+};
+
+export default createDeclarationModernSlaveryRows;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/create-declaration-modern-slavery-version-rows.ts b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/create-declaration-modern-slavery-version-rows.ts
new file mode 100644
index 0000000000..ac9f1b1d57
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/create-declaration-modern-slavery-version-rows.ts
@@ -0,0 +1,57 @@
+import { Connection } from 'mysql2/promise';
+import { DECLARATIONS } from '../../../../constants';
+import getAllDeclarationModernSlaveries from '../../../helpers/get-all-declaration-modern-slaveries';
+import createCuid from '../../../helpers/create-cuid';
+import executeSqlQuery from '../../../execute-sql-query';
+import { ApplicationDeclarationModernSlavery } from '../../../../types';
+
+const { WILL_ADHERE_TO_ALL_REQUIREMENTS, HAS_NO_OFFENSES_OR_INVESTIGATIONS, IS_NOT_AWARE_OF_EXISTING_SLAVERY } =
+  DECLARATIONS.LATEST_MODERN_SLAVERY_DECLARATIONS;
+
+/**
+ * createDeclarationModernSlaveryVersionRows
+ * For each modern slavery, create a new row in the DeclarationModernSlaveryVersion table.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery response
+ */
+const createDeclarationModernSlaveryVersionRows = async (connection: Connection) => {
+  const loggingMessage = 'Creating modern slavery version entries with modern slavery relationships';
+
+  console.info('✅ %s', loggingMessage);
+
+  try {
+    const modernSlaveries = await getAllDeclarationModernSlaveries(connection);
+
+    if (!modernSlaveries.length) {
+      console.info('ℹ️ No modern slavery entries available - no need to create declarationModernSlaveryVersion entries');
+
+      return false;
+    }
+
+    const versionPromises = modernSlaveries.map(async (modernSlavery: ApplicationDeclarationModernSlavery) => {
+      const { id: modernSlaveryId } = modernSlavery;
+
+      const idValues = `'${createCuid()}', '${modernSlaveryId}',`;
+
+      const versionValues = `'${WILL_ADHERE_TO_ALL_REQUIREMENTS}', '${HAS_NO_OFFENSES_OR_INVESTIGATIONS}', '${IS_NOT_AWARE_OF_EXISTING_SLAVERY}'`;
+
+      const theValues = `(${idValues} ${versionValues})`;
+
+      const query = await executeSqlQuery({
+        connection,
+        query: `INSERT INTO DeclarationModernSlaveryVersion (id, declarationModernSlavery, hasNoOffensesOrInvestigations, isNotAwareOfExistingSlavery, willAdhereToAllRequirements) VALUES ${theValues}`,
+        loggingMessage: `Creating DeclarationModernSlaveryVersion entry for modernSlavery ${modernSlaveryId}`,
+      });
+
+      return query;
+    });
+
+    return Promise.all(versionPromises);
+  } catch (error) {
+    console.error('🚨 Error %s %o', loggingMessage, error);
+
+    throw new Error(`🚨 error ${loggingMessage} ${error}`);
+  }
+};
+
+export default createDeclarationModernSlaveryVersionRows;
diff --git a/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/index.ts b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/index.ts
new file mode 100644
index 0000000000..75dc782124
--- /dev/null
+++ b/src/api/data-migration/version-3-to-version-4/update-applications/update-declarations/index.ts
@@ -0,0 +1,44 @@
+import { Connection } from 'mysql2/promise';
+import createDeclarationModernSlaveryRows from './create-declaration-modern-slavery-rows';
+import createDeclarationModernSlaveryVersionRows from './create-declaration-modern-slavery-version-rows';
+import addDeclarationModernSlaveryField from './add-declaration-modern-slavery-field';
+import addDeclarationModernSlaveryKeys from './add-declaration-modern-slavery-keys';
+import addDeclarationModernSlaveryConstraints from './add-declaration-modern-slavery-constraints';
+import addDeclarationModernSlaveryVersionKey from './add-declaration-modern-slavery-version-key';
+import addDeclarationModernSlaveryVersionConstraint from './add-declaration-modern-slavery-version-constraint';
+
+/**
+ * updateDeclarations
+ * Update declarations from the V3 data model/structure, to the V4 data model/structure.
+ * @param {Connection} connection: SQL database connection
+ * @returns {Promise<Array<object>>} executeSqlQuery responses
+ */
+const updateDeclarations = async (connection: Connection) => {
+  const loggingMessage = 'Updating declarations';
+
+  console.info('✅ %s', loggingMessage);
+
+  try {
+    const promises = await Promise.all([
+      await createDeclarationModernSlaveryRows(connection),
+
+      await createDeclarationModernSlaveryVersionRows(connection),
+
+      await addDeclarationModernSlaveryField(connection),
+
+      await addDeclarationModernSlaveryKeys(connection),
+      await addDeclarationModernSlaveryConstraints(connection),
+
+      await addDeclarationModernSlaveryVersionKey(connection),
+      await addDeclarationModernSlaveryVersionConstraint(connection),
+    ]);
+
+    return promises;
+  } catch (error) {
+    console.error('🚨 Error %s %o', loggingMessage, error);
+
+    throw new Error(`🚨 error ${loggingMessage} ${error}`);
+  }
+};
+
+export default updateDeclarations;
diff --git a/src/api/package-lock.json b/src/api/package-lock.json
index 1c0b43e2e1..d15ea582a4 100644
--- a/src/api/package-lock.json
+++ b/src/api/package-lock.json
@@ -17,6 +17,7 @@
         "@keystone-6/auth": "^7.0.3",
         "@keystone-6/core": "^5.8.0",
         "@keystone-6/fields-document": "^8.0.2",
+        "@paralleldrive/cuid2": "^2.2.2",
         "@types/express": "^5.0.0",
         "@types/overload-protection": "^1.2.4",
         "apollo-server-express": "^3.13.0",
@@ -27,7 +28,7 @@
         "exceljs": "^4.4.0",
         "express-rate-limit": "^7.4.1",
         "jsonwebtoken": "^9.0.2",
-        "mysql2": "^3.11.3",
+        "mysql2": "^3.11.5",
         "node-cron": "^3.0.3",
         "notifications-node-client": "^8.2.1",
         "otplib": "^12.0.1",
@@ -5416,6 +5417,18 @@
         "node": ">= 10"
       }
     },
+    "node_modules/@noble/hashes": {
+      "version": "1.6.1",
+      "resolved": "https://registry.npmjs.org/@noble/hashes/-/hashes-1.6.1.tgz",
+      "integrity": "sha512-pq5D8h10hHBjyqX+cfBm0i8JUXJ0UhczFc4r74zbuT9XgewFo2E3J1cOaGtdZynILNmQ685YWGzGE1Zv6io50w==",
+      "license": "MIT",
+      "engines": {
+        "node": "^14.21.3 || >=16"
+      },
+      "funding": {
+        "url": "https://paulmillr.com/funding/"
+      }
+    },
     "node_modules/@nodelib/fs.scandir": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/@nodelib/fs.scandir/-/fs.scandir-3.0.0.tgz",
@@ -5513,6 +5526,15 @@
         "@otplib/plugin-thirty-two": "^12.0.1"
       }
     },
+    "node_modules/@paralleldrive/cuid2": {
+      "version": "2.2.2",
+      "resolved": "https://registry.npmjs.org/@paralleldrive/cuid2/-/cuid2-2.2.2.tgz",
+      "integrity": "sha512-ZOBkgDwEdoYVlSeRbYYXs0S9MejQofiVYoTbKzy/6GQa39/q5tQU2IX46+shYnUkpEl3wc+J6wRlar7r2EK2xA==",
+      "license": "MIT",
+      "dependencies": {
+        "@noble/hashes": "^1.1.5"
+      }
+    },
     "node_modules/@pkgjs/parseargs": {
       "version": "0.11.0",
       "resolved": "https://registry.npmjs.org/@pkgjs/parseargs/-/parseargs-0.11.0.tgz",
@@ -18423,9 +18445,10 @@
       }
     },
     "node_modules/mysql2": {
-      "version": "3.11.3",
-      "resolved": "https://registry.npmjs.org/mysql2/-/mysql2-3.11.3.tgz",
-      "integrity": "sha512-Qpu2ADfbKzyLdwC/5d4W7+5Yz7yBzCU05YWt5npWzACST37wJsB23wgOSo00qi043urkiRwXtEvJc9UnuLX/MQ==",
+      "version": "3.11.5",
+      "resolved": "https://registry.npmjs.org/mysql2/-/mysql2-3.11.5.tgz",
+      "integrity": "sha512-0XFu8rUmFN9vC0ME36iBvCUObftiMHItrYFhlCRvFWbLgpNqtC4Br/NmZX1HNCszxT0GGy5QtP+k3Q3eCJPaYA==",
+      "license": "MIT",
       "dependencies": {
         "aws-ssl-profiles": "^1.1.1",
         "denque": "^2.1.0",
diff --git a/src/api/package.json b/src/api/package.json
index b10da9ea6f..439fa49865 100644
--- a/src/api/package.json
+++ b/src/api/package.json
@@ -14,7 +14,7 @@
   "author": "UK Export Finance",
   "scripts": {
     "build": "NODE_ENV=dev keystone build --no-ui",
-    "data-migration": "npx ts-node --transpile-only ./data-migration/version-2-to-version-3/index.ts",
+    "data-migration": "npx ts-node --transpile-only ./data-migration/version-3-to-version-4/index.ts",
     "dev": "keystone dev --no-ui",
     "documentation": "npx spectaql -t ./documentation/output ./documentation/config.yml",
     "lint": "eslint ./",
@@ -31,6 +31,7 @@
     "@keystone-6/auth": "^7.0.3",
     "@keystone-6/core": "^5.8.0",
     "@keystone-6/fields-document": "^8.0.2",
+    "@paralleldrive/cuid2": "^2.2.2",
     "@types/express": "^5.0.0",
     "@types/overload-protection": "^1.2.4",
     "apollo-server-express": "^3.13.0",
@@ -41,7 +42,7 @@
     "exceljs": "^4.4.0",
     "express-rate-limit": "^7.4.1",
     "jsonwebtoken": "^9.0.2",
-    "mysql2": "^3.11.3",
+    "mysql2": "^3.11.5",
     "node-cron": "^3.0.3",
     "notifications-node-client": "^8.2.1",
     "otplib": "^12.0.1",