diff --git a/server/src/controllers/asset-media.controller.spec.ts b/server/src/controllers/asset-media.controller.spec.ts
index eb594fbe47..bd5a4579ec 100644
--- a/server/src/controllers/asset-media.controller.spec.ts
+++ b/server/src/controllers/asset-media.controller.spec.ts
@@ -53,7 +53,7 @@ describe(AssetMediaController.name, () => {
     });
 
     it('should accept metadata', async () => {
-      const mobileMetadata = { key: AssetMetadataKey.MobileApp, value: { iCloudId: '123' } };
+      const mobileMetadata = { key: AssetMetadataKey.MobileApp, value: { iCloudId: '123', iCloudIdETag: 'etag123' } };
       const { status } = await request(ctx.getHttpServer())
         .post('/assets')
         .attach('assetData', assetData, filename)
@@ -98,6 +98,19 @@ describe(AssetMediaController.name, () => {
       expect(body).toEqual(factory.responses.badRequest(['metadata.0.value.iCloudId must be a string']));
     });
 
+    it('should validate iCloudIdETag is a string', async () => {
+      const { status, body } = await request(ctx.getHttpServer())
+        .post('/assets')
+        .attach('assetData', assetData, filename)
+        .field({
+          ...makeUploadDto(),
+          metadata: JSON.stringify([{ key: AssetMetadataKey.MobileApp, value: { iCloudIdETag: 123 } }]),
+        });
+
+      expect(status).toBe(400);
+      expect(body).toEqual(factory.responses.badRequest(['metadata.0.value.iCloudIdETag must be a string']));
+    });
+
     it('should require `deviceAssetId`', async () => {
       const { status, body } = await request(ctx.getHttpServer())
         .post('/assets')
diff --git a/server/src/controllers/asset.controller.spec.ts b/server/src/controllers/asset.controller.spec.ts
index 649c80e850..8e84bc9e46 100644
--- a/server/src/controllers/asset.controller.spec.ts
+++ b/server/src/controllers/asset.controller.spec.ts
@@ -190,6 +190,28 @@ describe(AssetController.name, () => {
 
     describe(AssetMetadataKey.MobileApp, () => {
       it('should accept valid data and pass to service correctly', async () => {
+        const assetId = factory.uuid();
+        const { status } = await request(ctx.getHttpServer())
+          .put(`/assets/${assetId}/metadata`)
+          .send({ items: [{ key: 'mobile-app', value: { iCloudId: '123', iCloudIdETag: 'etag123' } }] });
+        expect(service.upsertMetadata).toHaveBeenCalledWith(undefined, assetId, {
+          items: [{ key: 'mobile-app', value: { iCloudId: '123', iCloudIdETag: 'etag123' } }],
+        });
+        expect(status).toBe(200);
+      });
+
+      it('should work without iCloudId', async () => {
+        const assetId = factory.uuid();
+        const { status } = await request(ctx.getHttpServer())
+          .put(`/assets/${assetId}/metadata`)
+          .send({ items: [{ key: 'mobile-app', value: { iCloudIdETag: 'etag123' } }] });
+        expect(service.upsertMetadata).toHaveBeenCalledWith(undefined, assetId, {
+          items: [{ key: 'mobile-app', value: { iCloudIdETag: 'etag123' } }],
+        });
+        expect(status).toBe(200);
+      });
+
+      it('should work without iCloudIdETag', async () => {
         const assetId = factory.uuid();
         const { status } = await request(ctx.getHttpServer())
           .put(`/assets/${assetId}/metadata`)
@@ -200,7 +222,7 @@ describe(AssetController.name, () => {
         expect(status).toBe(200);
       });
 
-      it('should work without iCloudId', async () => {
+      it('should work with empty object', async () => {
         const assetId = factory.uuid();
         const { status } = await request(ctx.getHttpServer())
           .put(`/assets/${assetId}/metadata`)
diff --git a/server/src/dtos/asset.dto.ts b/server/src/dtos/asset.dto.ts
index dc43a0200c..215c9e85dc 100644
--- a/server/src/dtos/asset.dto.ts
+++ b/server/src/dtos/asset.dto.ts
@@ -177,6 +177,10 @@ export class AssetMetadataMobileAppDto {
   @IsString()
   @Optional()
   iCloudId?: string;
+
+  @IsString()
+  @Optional()
+  iCloudIdETag?: string;
 }
 
 export class AssetMetadataResponseDto {
diff --git a/server/src/types.ts b/server/src/types.ts
index afc72480e8..742f162e56 100644
--- a/server/src/types.ts
+++ b/server/src/types.ts
@@ -551,5 +551,5 @@ export type AssetMetadataItem<T extends keyof AssetMetadata = AssetMetadataKey>
 };
 
 export interface AssetMetadata extends Record<AssetMetadataKey, Record<string, any>> {
-  [AssetMetadataKey.MobileApp]: { iCloudId: string };
+  [AssetMetadataKey.MobileApp]: { iCloudId: string; iCloudIdETag: string };
 }
diff --git a/server/test/medium/specs/sync/sync-asset-metadata.spec.ts b/server/test/medium/specs/sync/sync-asset-metadata.spec.ts
index 8ba9630520..99455ffdc5 100644
--- a/server/test/medium/specs/sync/sync-asset-metadata.spec.ts
+++ b/server/test/medium/specs/sync/sync-asset-metadata.spec.ts
@@ -23,7 +23,9 @@ describe(SyncEntityType.AssetMetadataV1, () => {
 
     const assetRepo = ctx.get(AssetRepository);
     const { asset } = await ctx.newAsset({ ownerId: user.id });
-    await assetRepo.upsertMetadata(asset.id, [{ key: AssetMetadataKey.MobileApp, value: { iCloudId: 'abc123' } }]);
+    await assetRepo.upsertMetadata(asset.id, [
+      { key: AssetMetadataKey.MobileApp, value: { iCloudId: 'abc123', iCloudIdETag: 'etag123' } },
+    ]);
 
     const response = await ctx.syncStream(auth, [SyncRequestType.AssetMetadataV1]);
     expect(response).toEqual([
@@ -32,7 +34,7 @@ describe(SyncEntityType.AssetMetadataV1, () => {
         data: {
           key: AssetMetadataKey.MobileApp,
           assetId: asset.id,
-          value: { iCloudId: 'abc123' },
+          value: { iCloudId: 'abc123', iCloudIdETag: 'etag123' },
         },
         type: 'AssetMetadataV1',
       },
@@ -48,7 +50,9 @@ describe(SyncEntityType.AssetMetadataV1, () => {
 
     const assetRepo = ctx.get(AssetRepository);
     const { asset } = await ctx.newAsset({ ownerId: user.id });
-    await assetRepo.upsertMetadata(asset.id, [{ key: AssetMetadataKey.MobileApp, value: { iCloudId: 'abc123' } }]);
+    await assetRepo.upsertMetadata(asset.id, [
+      { key: AssetMetadataKey.MobileApp, value: { iCloudId: 'abc123', iCloudIdETag: 'etag123' } },
+    ]);
 
     const response = await ctx.syncStream(auth, [SyncRequestType.AssetMetadataV1]);
     expect(response).toEqual([
@@ -57,7 +61,7 @@ describe(SyncEntityType.AssetMetadataV1, () => {
         data: {
           key: AssetMetadataKey.MobileApp,
           assetId: asset.id,
-          value: { iCloudId: 'abc123' },
+          value: { iCloudId: 'abc123', iCloudIdETag: 'etag123' },
         },
         type: 'AssetMetadataV1',
       },
@@ -66,7 +70,9 @@ describe(SyncEntityType.AssetMetadataV1, () => {
 
     await ctx.syncAckAll(auth, response);
 
-    await assetRepo.upsertMetadata(asset.id, [{ key: AssetMetadataKey.MobileApp, value: { iCloudId: 'abc456' } }]);
+    await assetRepo.upsertMetadata(asset.id, [
+      { key: AssetMetadataKey.MobileApp, value: { iCloudId: 'abc456', iCloudIdETag: 'etag456' } },
+    ]);
 
     const updatedResponse = await ctx.syncStream(auth, [SyncRequestType.AssetMetadataV1]);
     expect(updatedResponse).toEqual([
@@ -75,7 +81,7 @@ describe(SyncEntityType.AssetMetadataV1, () => {
         data: {
           key: AssetMetadataKey.MobileApp,
           assetId: asset.id,
-          value: { iCloudId: 'abc456' },
+          value: { iCloudId: 'abc456', iCloudIdETag: 'etag456' },
         },
         type: 'AssetMetadataV1',
       },
@@ -93,7 +99,9 @@ describe(SyncEntityType.AssetMetadataDeleteV1, () => {
 
     const assetRepo = ctx.get(AssetRepository);
     const { asset } = await ctx.newAsset({ ownerId: user.id });
-    await assetRepo.upsertMetadata(asset.id, [{ key: AssetMetadataKey.MobileApp, value: { iCloudId: 'abc123' } }]);
+    await assetRepo.upsertMetadata(asset.id, [
+      { key: AssetMetadataKey.MobileApp, value: { iCloudId: 'abc123', iCloudIdETag: 'etag123' } },
+    ]);
 
     const response = await ctx.syncStream(auth, [SyncRequestType.AssetMetadataV1]);
     expect(response).toEqual([
@@ -102,7 +110,7 @@ describe(SyncEntityType.AssetMetadataDeleteV1, () => {
         data: {
           key: AssetMetadataKey.MobileApp,
           assetId: asset.id,
-          value: { iCloudId: 'abc123' },
+          value: { iCloudId: 'abc123', iCloudIdETag: 'etag123' },
         },
         type: 'AssetMetadataV1',
       },