diff --git a/src/libs/actions/IOU/SplitTransactionUpdate.ts b/src/libs/actions/IOU/SplitTransactionUpdate.ts
index 892df2ab762e..bb5ec2fe53a9 100644
--- a/src/libs/actions/IOU/SplitTransactionUpdate.ts
+++ b/src/libs/actions/IOU/SplitTransactionUpdate.ts
@@ -211,6 +211,7 @@ function updateSplitTransactions({
                 created: split.created,
                 merchant: split?.merchant ?? '',
                 transactionID: split.transactionID,
+                reportID: split.reportID,
                 comment: {
                     comment: currentDescription,
                 },
@@ -225,7 +226,7 @@ function updateSplitTransactions({
         }) ?? [];
     changesInReportTotal -= splitExpensesTotal;
 
-    const onyxData: OnyxData<BuildOnyxDataForMoneyRequestKeys | UpdateMoneyRequestDataKeys> = {
+    const onyxData: OnyxData<BuildOnyxDataForMoneyRequestKeys | UpdateMoneyRequestDataKeys | typeof ONYXKEYS.COLLECTION.SPLIT_TRANSACTION_DRAFT> = {
         successData: [],
         failureData: [],
         optimisticData: [],
@@ -476,6 +477,7 @@ function updateSplitTransactions({
                 comment: currentSplit?.comment?.comment,
                 customUnitRateID: currentSplit?.customUnitRateID ?? CONST.CUSTOM_UNITS.FAKE_P2P_ID,
             } as TransactionChanges;
+            delete transactionChanges.reportID;
 
             const existing = getTransactionDetails(splitTransaction);
             const oldTransactionChanges = {
@@ -1258,6 +1260,29 @@ function updateSplitTransactions({
         }
     }
 
+    if (!isCreationOfSplits && !isReverseSplitOperation) {
+        const splitUpdateFailureDataKeys: Array<`${typeof ONYXKEYS.COLLECTION.TRANSACTION}${string}` | `${typeof ONYXKEYS.COLLECTION.SPLIT_TRANSACTION_DRAFT}${string}`> = [
+            `${ONYXKEYS.COLLECTION.SPLIT_TRANSACTION_DRAFT}${originalTransactionID}`,
+            `${ONYXKEYS.COLLECTION.TRANSACTION}${originalTransactionID}`,
+            ...splitExpenses.filter((splitExpense) => !!splitExpense.transactionID).map((splitExpense) => `${ONYXKEYS.COLLECTION.TRANSACTION}${splitExpense.transactionID}` as const),
+        ];
+
+        for (const key of new Set(splitUpdateFailureDataKeys)) {
+            onyxData.failureData?.push(
+                {
+                    onyxMethod: Onyx.METHOD.MERGE,
+                    key,
+                    value: {errors: null},
+                },
+                {
+                    onyxMethod: Onyx.METHOD.MERGE,
+                    key,
+                    value: {errors: getMicroSecondOnyxErrorWithTranslationKey('iou.error.genericEditFailureMessage')},
+                },
+            );
+        }
+    }
+
     if (isReverseSplitOperation) {
         const parameters = {
             ...splits.at(0),
diff --git a/tests/actions/IOUTest/SplitTest.ts b/tests/actions/IOUTest/SplitTest.ts
index ec8ad0d6e574..c5b36ff33a4d 100644
--- a/tests/actions/IOUTest/SplitTest.ts
+++ b/tests/actions/IOUTest/SplitTest.ts
@@ -48,7 +48,7 @@ import {createRandomReport} from '../../utils/collections/reports';
 import createRandomTransaction from '../../utils/collections/transaction';
 import getOnyxValue from '../../utils/getOnyxValue';
 import type {MockFetch} from '../../utils/TestHelper';
-import {getGlobalFetchMock, getOnyxData} from '../../utils/TestHelper';
+import {getGlobalFetchMock, getOnyxData, translateLocal} from '../../utils/TestHelper';
 import waitForBatchedUpdates from '../../utils/waitForBatchedUpdates';
 import waitForNetworkPromises from '../../utils/waitForNetworkPromises';
 
@@ -4266,6 +4266,84 @@ describe('updateSplitTransactions', () => {
         return {splitTransactionID1, splitTransactionID2, splitTransactionID3};
     };
 
+    it('should send reportID and localized failure fallback when updating existing split transactions', async () => {
+        const {expenseReport, originalTransactionID} = await createBaseExpense();
+
+        if (!originalTransactionID || !expenseReport?.reportID) {
+            throw new Error('Missing original transaction data');
+        }
+
+        const iouAction = getIOUActionForReportID(expenseReport.reportID, originalTransactionID);
+        const {splitTransactionID1, splitTransactionID2} = await splitToTwo(expenseReport, originalTransactionID, iouAction);
+        const splitTransaction1 = await getOnyxValue(`${ONYXKEYS.COLLECTION.TRANSACTION}${splitTransactionID1}`);
+        const splitTransaction2 = await getOnyxValue(`${ONYXKEYS.COLLECTION.TRANSACTION}${splitTransactionID2}`);
+        const {allTransactions, allReports, allReportNameValuePairs} = await getCollections();
+        const policyTags = await getPolicyTags(expenseReport.reportID);
+        const reports = getTransactionAndExpenseReports(expenseReport.reportID);
+
+        const APIlib = require('@libs/API') as {write: (...args: unknown[]) => Promise<void>};
+        const originalWrite = APIlib.write;
+        const writeSpy = jest.spyOn(APIlib, 'write').mockImplementation((...args) => originalWrite(...args));
+
+        updateSplitTransactions({
+            allTransactionsList: allTransactions,
+            allReportsList: allReports,
+            allReportNameValuePairsList: allReportNameValuePairs,
+            transactionData: {
+                reportID: expenseReport.reportID,
+                originalTransactionID,
+                splitExpenses: [
+                    {transactionID: splitTransactionID1, reportID: splitTransaction1?.reportID, amount: amount / 2 + 100, created: DateUtils.getDBTime()},
+                    {transactionID: splitTransactionID2, reportID: splitTransaction2?.reportID, amount: amount / 2 - 100, created: DateUtils.getDBTime()},
+                ],
+                splitExpensesTotal: amount,
+            },
+            searchContext: {currentSearchHash: -2},
+            policyCategories: undefined,
+            policy: undefined,
+            policyRecentlyUsedCategories: [],
+            iouReport: expenseReport,
+            firstIOU: undefined,
+            isASAPSubmitBetaEnabled: false,
+            currentUserPersonalDetails,
+            transactionViolations: {},
+            policyRecentlyUsedCurrencies: [],
+            quickAction: undefined,
+            iouReportNextStep: undefined,
+            betas: [CONST.BETAS.ALL],
+            policyTags,
+            personalDetails: {[RORY_ACCOUNT_ID]: {accountID: RORY_ACCOUNT_ID, login: RORY_EMAIL}},
+            transactionReport: reports.transactionReport,
+            expenseReport: reports.expenseReport,
+            isOffline: false,
+        });
+
+        const updateSplitTransactionCall = writeSpy.mock.calls.find(([command]) => command === WRITE_COMMANDS.UPDATE_SPLIT_TRANSACTION);
+        writeSpy.mockRestore();
+
+        expect(updateSplitTransactionCall).toBeDefined();
+        const [, params, onyxData] = updateSplitTransactionCall ?? [];
+        const updateParams = params as Record<string, string | number | boolean>;
+        expect(updateParams['splits[0][reportID]']).toBe(splitTransaction1?.reportID);
+        expect(updateParams['splits[1][reportID]']).toBe(splitTransaction2?.reportID);
+
+        const failureData = (onyxData as {failureData?: Array<{key: string; value?: {errors?: Record<string, string | null> | null}}>})?.failureData ?? [];
+        const getFailureErrorUpdates = (key: string) =>
+            failureData.filter((update) => update.key === key && update.value && Object.hasOwn(update.value, 'errors')).map((update) => update.value?.errors);
+
+        const localizedFallback = translateLocal('iou.error.genericEditFailureMessage');
+        const draftFailureErrors = getFailureErrorUpdates(`${ONYXKEYS.COLLECTION.SPLIT_TRANSACTION_DRAFT}${originalTransactionID}`);
+        const originalTransactionFailureErrors = getFailureErrorUpdates(`${ONYXKEYS.COLLECTION.TRANSACTION}${originalTransactionID}`);
+        const splitTransactionFailureErrors = getFailureErrorUpdates(`${ONYXKEYS.COLLECTION.TRANSACTION}${splitTransactionID1}`);
+
+        expect(draftFailureErrors.slice(-2)).toEqual([null, expect.any(Object)]);
+        expect(Object.values(draftFailureErrors.at(-1) ?? {}).at(0)).toBe(localizedFallback);
+        expect(originalTransactionFailureErrors.slice(-2)).toEqual([null, expect.any(Object)]);
+        expect(Object.values(originalTransactionFailureErrors.at(-1) ?? {}).at(0)).toBe(localizedFallback);
+        expect(splitTransactionFailureErrors.slice(-2)).toEqual([null, expect.any(Object)]);
+        expect(Object.values(splitTransactionFailureErrors.at(-1) ?? {}).at(0)).toBe(localizedFallback);
+    });
+
     it('should keep all split transactions on hold when splitting a held transaction', async () => {
         const {expenseReport, transactionThreadReportID, originalTransactionID} = await createBaseExpense();
         const {allReports, allReportActions} = await getCollections();