diff --git a/eq-author-api/src/validation/customKeywords/validateSurveyId.js b/eq-author-api/src/validation/customKeywords/validateSurveyId.js
index c3853d86ad..5d97110391 100644
--- a/eq-author-api/src/validation/customKeywords/validateSurveyId.js
+++ b/eq-author-api/src/validation/customKeywords/validateSurveyId.js
@@ -1,6 +1,8 @@
 const createValidationError = require("../createValidationError");
 const {
   ERR_SURVEY_ID_MISMATCH,
+  ERR_INVALID,
+  ERR_VALID_REQUIRED,
 } = require("../../../constants/validationErrorCodes");
 
 module.exports = (ajv) =>
@@ -19,8 +21,37 @@ module.exports = (ajv) =>
       // Get the supplementary data from the questionnaire object
       const supplementaryData = questionnaire.supplementaryData;
 
-      // If supplementaryData exists and contains a surveyId, and supplementaryData's surveyId doesn't match the questionnaire's surveyId, throw a validation error
       if (
+        typeof questionnaire.surveyId === "string" &&
+        questionnaire.surveyId.length === 0
+      ) {
+        isValid.errors = [
+          createValidationError(
+            instancePath,
+            fieldName,
+            ERR_VALID_REQUIRED,
+            questionnaire,
+            ERR_VALID_REQUIRED
+          ),
+        ];
+        return false;
+      } else if (
+        typeof questionnaire.surveyId === "string" &&
+        questionnaire.surveyId.length > 0 &&
+        !questionnaire.surveyId.match(/^\d{3}$/)
+      ) {
+        isValid.errors = [
+          createValidationError(
+            instancePath,
+            fieldName,
+            ERR_INVALID,
+            questionnaire,
+            ERR_INVALID
+          ),
+        ];
+        return false;
+        // If supplementaryData exists and contains a surveyId, and supplementaryData's surveyId doesn't match the questionnaire's surveyId, throw a validation error
+      } else if (
         supplementaryData &&
         supplementaryData.surveyId &&
         questionnaireSurveyId !== supplementaryData.surveyId
@@ -34,9 +65,10 @@ module.exports = (ajv) =>
             ERR_SURVEY_ID_MISMATCH
           ),
         ];
+
         return false;
+      } else {
+        return true;
       }
-
-      return true;
     },
   });
diff --git a/eq-author-api/src/validation/index.test.js b/eq-author-api/src/validation/index.test.js
index 914fb448b9..7038dbf4fc 100644
--- a/eq-author-api/src/validation/index.test.js
+++ b/eq-author-api/src/validation/index.test.js
@@ -38,6 +38,7 @@ const {
   CALCSUM_MOVED,
   ERR_SEC_CONDITION_NOT_SELECTED,
   ERR_COUNT_OF_GREATER_THAN_AVAILABLE_OPTIONS,
+  ERR_SURVEY_ID_MISMATCH,
 } = require("../../constants/validationErrorCodes");
 
 const validation = require(".");
@@ -151,6 +152,10 @@ describe("schema validation", () => {
           ],
         },
       ],
+      supplementaryData: {
+        id: "supplementary_dataset_schema",
+        surveyId: "123",
+      },
       metadata: [
         {
           id: "87c64b20-9662-408b-b674-e2403e90dad3",
@@ -198,7 +203,7 @@ describe("schema validation", () => {
 
   describe("Themes validation", () => {
     it("should return an error if survey ID missing", () => {
-      questionnaire.surveyId = null;
+      questionnaire.surveyId = "";
       const errors = validation(questionnaire);
       expect(errors[0].errorCode).toBe(ERR_VALID_REQUIRED);
     });
@@ -210,11 +215,16 @@ describe("schema validation", () => {
     });
 
     it("should return an error if survey ID is missing on a social survey", () => {
-      questionnaire.surveyId = null;
+      questionnaire.surveyId = "";
       questionnaire.type = "Social";
       const errors = validation(questionnaire);
       expect(errors[0].errorCode).toBe(ERR_VALID_REQUIRED);
     });
+    it("should return an error if survey ID does not match with supplementary dataset schema’s survey ID", () => {
+      questionnaire.surveyId = "111";
+      const errors = validation(questionnaire);
+      expect(errors[0].errorCode).toBe(ERR_SURVEY_ID_MISMATCH);
+    });
   });
 
   describe("Question page validation", () => {
diff --git a/eq-author-api/src/validation/schemas/questionnaire.json b/eq-author-api/src/validation/schemas/questionnaire.json
index 85b46ca871..acbbad80b2 100644
--- a/eq-author-api/src/validation/schemas/questionnaire.json
+++ b/eq-author-api/src/validation/schemas/questionnaire.json
@@ -26,25 +26,7 @@
       "$ref": "submission.json"
     },
     "surveyId": {
-      "allOf": [
-        {
-          "if": {
-            "type": "string",
-            "minLength": 1
-          },
-          "then": {
-            "type": "string",
-            "pattern": "^\\d{3}$",
-            "errorMessage": "ERR_INVALID"
-          },
-          "else": {
-            "$ref": "definitions.json#/definitions/populatedString"
-          }
-        },
-        {
-          "validateSurveyId": true
-        }
-      ]
+      "validateSurveyId": true
     },
     "formType": {
       "if": {