diff --git a/app/src/services/sync.js b/app/src/services/sync.js
index af12478c..2f664498 100644
--- a/app/src/services/sync.js
+++ b/app/src/services/sync.js
@@ -328,17 +328,25 @@ const service = {
       const comsTags = comsTagsForVersion[0]?.tagset ?? [];
       // S3 Tags
       const s3Tags = toLowerKeys(s3TagsForVersion?.TagSet ?? []);
-
-      // Ensure `coms-id` tag exists on this version in S3
-      if (s3Tags.length < 10 && !s3Tags.find(s3T => s3T.key === 'coms-id')) {
+      /**
+       * Add coms-id tag to latest version in S3 if not already present
+       * NOTE: For a sync job the _deriveObjectId() function will have already added
+       * the coms-id to latest version.
+       * TODO: check if this version is still also the latest on corresponding version in S3
+       */
+      if (comsVersion.isLatest && s3Tags.length < 10 && !s3Tags.find(s3T => s3T.key === 'coms-id')) {
+        /**
+         * NOTE: adding tags to a specified version (passing a `VersionId` parameter) will affect `Last Modified`
+         * attribute of multiple versions on some s3 storage providors including Dell ECS
+         */
         await storageService.putObjectTagging({
           filePath: path,
           tags: (s3TagsForVersion?.TagSet ?? []).concat([{
             Key: 'coms-id',
             Value: comsVersion.objectId
           }]),
-          s3VersionId: comsVersion.s3VersionId,
           bucketId: bucketId,
+          // s3VersionId: comsVersion.s3VersionId,
         });
         // add to our arrays for comaprison
         s3Tags.push({ key: 'coms-id', value: comsVersion.objectId });
diff --git a/app/tests/unit/services/sync.spec.js b/app/tests/unit/services/sync.spec.js
index a727a3e8..f4d525ce 100644
--- a/app/tests/unit/services/sync.spec.js
+++ b/app/tests/unit/services/sync.spec.js
@@ -825,7 +825,8 @@ describe('syncTags', () => {
   const comsVersion = {
     id: validUuidv4,
     objectId: validUuidv4,
-    s3VersionId: validUuidv4
+    s3VersionId: validUuidv4,
+    isLatest: true
   };
 
   beforeEach(() => {
@@ -898,7 +899,6 @@ describe('syncTags', () => {
         Key: 'coms-id',
         Value: comsVersion.objectId
       }]),
-      s3VersionId: comsVersion.s3VersionId,
       bucketId: bucketId,
     }));
     expect(versionTrx.commit).toHaveBeenCalledTimes(1);
@@ -940,7 +940,75 @@ describe('syncTags', () => {
         Key: 'coms-id',
         Value: comsVersion.objectId
       }]),
+      bucketId: bucketId,
+    }));
+    expect(versionTrx.commit).toHaveBeenCalledTimes(1);
+  });
+
+  it('should not write coms-id tag when coms version is not latest', async () => {
+    fetchTagsForVersionSpy.mockResolvedValue([{}]);
+    getObjectTaggingSpy.mockResolvedValue({});
+    putObjectTaggingSpy.mockResolvedValue({});
+
+    comsVersion.isLatest = false;
+    const result = await service.syncTags(comsVersion, path, bucketId);
+    // reset for other tests
+    comsVersion.isLatest = true;
+
+    expect(result).toBeTruthy();
+    expect(Array.isArray(result)).toBeTruthy();
+    expect(result).toHaveLength(0);
+
+    expect(Version.startTransaction).toHaveBeenCalledTimes(1);
+    expect(associateTagsSpy).toHaveBeenCalledTimes(0);
+    expect(dissociateTagsSpy).toHaveBeenCalledTimes(0);
+    expect(fetchTagsForVersionSpy).toHaveBeenCalledTimes(1);
+    expect(fetchTagsForVersionSpy).toHaveBeenCalledWith(expect.objectContaining({
+      versionIds: comsVersion.id
+    }), expect.any(Object));
+    expect(getObjectTaggingSpy).toHaveBeenCalledTimes(1);
+    expect(getObjectTaggingSpy).toHaveBeenCalledWith(expect.objectContaining({
+      filePath: path,
       s3VersionId: comsVersion.s3VersionId,
+      bucketId: bucketId
+    }));
+    expect(getSpy).toHaveBeenCalledTimes(0);
+    expect(putObjectTaggingSpy).toHaveBeenCalledTimes(0);
+    expect(versionTrx.commit).toHaveBeenCalledTimes(1);
+  });
+
+  it('should write coms-id tag when coms version is latest', async () => {
+    fetchTagsForVersionSpy.mockResolvedValue([{}]);
+    getObjectTaggingSpy.mockResolvedValue({});
+    putObjectTaggingSpy.mockResolvedValue({});
+
+    const result = await service.syncTags(comsVersion, path, bucketId);
+
+    expect(result).toBeTruthy();
+    expect(Array.isArray(result)).toBeTruthy();
+    expect(result).toHaveLength(1);
+
+    expect(Version.startTransaction).toHaveBeenCalledTimes(1);
+    expect(associateTagsSpy).toHaveBeenCalledTimes(1);
+    expect(dissociateTagsSpy).toHaveBeenCalledTimes(0);
+    expect(fetchTagsForVersionSpy).toHaveBeenCalledTimes(1);
+    expect(fetchTagsForVersionSpy).toHaveBeenCalledWith(expect.objectContaining({
+      versionIds: comsVersion.id
+    }), expect.any(Object));
+    expect(getObjectTaggingSpy).toHaveBeenCalledTimes(1);
+    expect(getObjectTaggingSpy).toHaveBeenCalledWith(expect.objectContaining({
+      filePath: path,
+      s3VersionId: comsVersion.s3VersionId,
+      bucketId: bucketId
+    }));
+    expect(getSpy).toHaveBeenCalledTimes(0);
+    expect(putObjectTaggingSpy).toHaveBeenCalledTimes(1);
+    expect(putObjectTaggingSpy).toHaveBeenCalledWith(expect.objectContaining({
+      filePath: path,
+      tags: expect.arrayContaining([{
+        Key: 'coms-id',
+        Value: comsVersion.objectId
+      }]),
       bucketId: bucketId,
     }));
     expect(versionTrx.commit).toHaveBeenCalledTimes(1);