diff --git a/tests/constants/api_constants.ts b/tests/constants/api_constants.ts
index 53e1d703..e90c1d14 100644
--- a/tests/constants/api_constants.ts
+++ b/tests/constants/api_constants.ts
@@ -1,8 +1,17 @@
 export const SUPPLIER_LETTERS = 'letters';
-export const SUPPLIER_API_URL_SANDBOX = 'https://internal-dev-sandbox.api.service.nhs.uk/nhs-notify-supplier';
 export const AWS_REGION = 'eu-west-2';
 export const envName = process.env.PR_NUMBER ?? 'main';
 export const API_NAME = `nhs-${envName}-supapi`;
 export const LETTERSTABLENAME = `nhs-${envName}-supapi-letters`;
 export const SUPPLIERID = 'TestSupplier1';
 export const MI_ENDPOINT = 'mi';
+
+const formattedPr = process.env.PR_NUMBER
+  ? process.env.PR_NUMBER.replace(/^pr(\d+)$/i, "PR-$1")
+  : null;
+
+// Build sandbox environment name
+const sandboxEnv = formattedPr
+  ? `nhs-notify-supplier-${formattedPr}`
+  : "nhs-notify-supplier";
+export const SUPPLIER_API_URL_SANDBOX = `https://internal-dev-sandbox.api.service.nhs.uk/${sandboxEnv}`;
diff --git a/tests/helpers/generate_fetch_testData.ts b/tests/helpers/generate_fetch_testData.ts
index 2fd63aa6..069e7886 100644
--- a/tests/helpers/generate_fetch_testData.ts
+++ b/tests/helpers/generate_fetch_testData.ts
@@ -29,6 +29,7 @@ export async function createTestData(supplierId: string): Promise<void> {
     supplierId: supplierId,
     environment: envName,
     awsAccountId: '820178564574',
+    letterId: 'letterId',
     groupId: 'TestGroupID',
     specificationId: 'TestSpecificationID',
     status: 'PENDING',
diff --git a/tests/helpers/pnpmHelpers.ts b/tests/helpers/pnpmHelpers.ts
index e0e748c0..4a55ca9e 100644
--- a/tests/helpers/pnpmHelpers.ts
+++ b/tests/helpers/pnpmHelpers.ts
@@ -11,6 +11,7 @@ export async function runCreateLetter(options: {
   supplierId: string;
   environment: string;
   awsAccountId: string;
+  letterId: string;
   groupId: string;
   specificationId: string;
   status: string;
@@ -21,6 +22,7 @@ export async function runCreateLetter(options: {
     supplierId,
     environment,
     awsAccountId,
+    letterId,
     groupId,
     specificationId,
     status,
@@ -46,6 +48,8 @@ export async function runCreateLetter(options: {
     environment,
     '--awsAccountId',
     awsAccountId,
+    '--letter-id',
+    letterId,
     '--group-id',
     groupId,
     '--specification-id',
diff --git a/tests/sandbox/testCases/updateLetterStatus_testCases.ts b/tests/sandbox/testCases/updateLetterStatus_testCases.ts
index a22f3675..b81ca167 100644
--- a/tests/sandbox/testCases/updateLetterStatus_testCases.ts
+++ b/tests/sandbox/testCases/updateLetterStatus_testCases.ts
@@ -16,8 +16,8 @@ export type ApiSandboxUpdateLetterStatusTestData = {
 
 export const apiSandboxUpdateLetterStatusTestData: ApiSandboxUpdateLetterStatusTestData[] = [
   {
-    testCase: '200 response if record is updated with status PENDING',
-    id: '2WL5eYSWGzCHlGmzNxuqVusPxDg',
+    testCase: '202 response if record is updated with status PENDING',
+    id: '24L5eYSWGzCHlGmzNxuqVusPxDg',
     header: sandBoxHeader,
     body: {
       data: {
@@ -28,22 +28,12 @@ export const apiSandboxUpdateLetterStatusTestData: ApiSandboxUpdateLetterStatusT
         },
       }
     },
-    expectedStatus: 200,
-        expectedResponse: {
-      data: {
-        type: 'Letter',
-        id: '2WL5eYSWGzCHlGmzNxuqVusPxDg',
-        attributes: {
-          status: 'PENDING',
-          specificationId:'2WL5eYSWGzCHlGmzNxuqVusPxDg',
-        },
-      }
-    },
+    expectedStatus: 202,
   },
 
   {
-    testCase: '200 response if record is updated with status REJECTED',
-    id: '2WL5eYSWGzCHlGmzNxuqVusPxDg',
+    testCase: '202 response if record is updated with status REJECTED',
+    id: '24L5eYSWGzCHlGmzNxuqVusPxDg',
     header: sandBoxHeader,
     body: {
       data: {
@@ -51,24 +41,12 @@ export const apiSandboxUpdateLetterStatusTestData: ApiSandboxUpdateLetterStatusT
         id: '2WL5eYSWGzCHlGmzNxuqVusPxDg',
         attributes: {
           status: 'REJECTED',
-          reasonCode: 'R01',
-          reasonText: 'failed validation',
-        },
-      }
-    },
-    expectedStatus: 200,
-        expectedResponse: {
-      data: {
-        type: 'Letter',
-        id: '2WL5eYSWGzCHlGmzNxuqVusPxDg',
-        attributes: {
-          reasonCode: 'R01',
-          reasonText: 'failed validation',
-          status: 'REJECTED',
-          specificationId:'2WL5eYSWGzCHlGmzNxuqVusPxDg',
+          reasonCode: 'R07',
+          reasonText: 'No such address',
         },
       }
     },
+    expectedStatus: 202,
   },
   {
     testCase: '404 response if no resource is found for the given id',
diff --git a/tests/sandbox/testCases/updateMultipleStatus_testCases.ts b/tests/sandbox/testCases/updateMultipleStatus_testCases.ts
index dd6fdc7b..c312a334 100644
--- a/tests/sandbox/testCases/updateMultipleStatus_testCases.ts
+++ b/tests/sandbox/testCases/updateMultipleStatus_testCases.ts
@@ -23,7 +23,7 @@ type postRequest = {
 
 export const apiSandboxMultipleLetterStatusTestData: ApiSandboxUpdateLetterStatusTestData[] =
 [{
-    testCase: '200 response if records are updated',
+    testCase: '202 response if records are updated',
     header: sandBoxHeader,
     body:{
         data :
@@ -106,7 +106,7 @@ export const apiSandboxMultipleLetterStatusTestData: ApiSandboxUpdateLetterStatu
             type: 'Letter'
         }
     ]},
-    expectedStatus: 200
+    expectedStatus: 202
 },
 {
     testCase: '404 response if invalid request is passed',
diff --git a/tests/sandbox/updateLetterStatus.spec.ts b/tests/sandbox/updateLetterStatus.spec.ts
index 9e0d9a4d..02d9d9b7 100644
--- a/tests/sandbox/updateLetterStatus.spec.ts
+++ b/tests/sandbox/updateLetterStatus.spec.ts
@@ -7,16 +7,18 @@ test.describe('Sandbox Tests To Update Letter Status', () =>
 {
   apiSandboxUpdateLetterStatusTestData.forEach(({ testCase, header, id, body, expectedStatus, expectedResponse }) => {
     test(`Patch /Letters endpoint returns ${testCase}`, async ({ request }) => {
-
         const response = await request.patch(`${SUPPLIER_API_URL_SANDBOX}/${SUPPLIER_LETTERS}/${id}` ,{
                 headers: header,
                 data: body
           });
 
-        const res = await response.json();
-        expect(response.status()).toBe(expectedStatus);
-        expect(res).toEqual(expectedResponse);
+        console.log("URL", `${SUPPLIER_API_URL_SANDBOX}/${SUPPLIER_LETTERS}/${id}`);
 
+        expect(response.status()).toBe(expectedStatus);
+        if (response.status() != 202){
+          const res = await response.json();
+          expect(res).toEqual(expectedResponse);
+        }
     });
   });
 });