diff --git a/keyserver/src/creators/farcaster-channel-tag-creator.js b/keyserver/src/creators/farcaster-channel-tag-creator.js
--- a/keyserver/src/creators/farcaster-channel-tag-creator.js
+++ b/keyserver/src/creators/farcaster-channel-tag-creator.js
@@ -12,10 +12,17 @@
 } from 'lib/types/community-types.js';
 import { ServerError } from 'lib/utils/errors.js';
 
+import {
+  dbQuery,
+  SQL,
+  MYSQL_DUPLICATE_ENTRY_FOR_KEY_ERROR_CODE,
+} from '../database/database.js';
+import { fetchCommunityInfos } from '../fetchers/community-fetchers.js';
 import {
   uploadBlob,
   assignHolder,
   download,
+  deleteBlob,
   type BlobOperationResult,
   type BlobDownloadResult,
 } from '../services/blob.js';
@@ -25,13 +32,22 @@
   viewer: Viewer,
   request: CreateOrUpdateFarcasterChannelTagRequest,
 ): Promise<CreateOrUpdateFarcasterChannelTagResponse> {
-  const { commCommunityID, farcasterChannelID } = request;
-
   if (DISABLE_TAGGING_FARCASTER_CHANNEL) {
     throw new ServerError('internal_error');
   }
 
-  const blobDownload = await getFarcasterChannelTagBlob(farcasterChannelID);
+  const [serverCommunityInfos, blobDownload] = await Promise.all([
+    fetchCommunityInfos(viewer),
+    getFarcasterChannelTagBlob(request.farcasterChannelID),
+  ]);
+
+  const communityInfo = serverCommunityInfos.find(
+    community => community.id === request.commCommunityID,
+  );
+
+  if (!communityInfo) {
+    throw new ServerError('invalid_parameters');
+  }
 
   if (blobDownload.found) {
     throw new ServerError('already_in_use');
@@ -40,8 +56,8 @@
   const blobHolder = uuid.v4();
 
   const blobResult = await uploadFarcasterChannelTagBlob(
-    commCommunityID,
-    farcasterChannelID,
+    request.commCommunityID,
+    request.farcasterChannelID,
     blobHolder,
   );
 
@@ -53,9 +69,62 @@
     }
   }
 
+  const query = SQL`
+    START TRANSACTION;
+
+    SELECT farcaster_channel_id, blob_holder
+    INTO @currentFarcasterChannelID, @currentBlobHolder
+    FROM communities
+    WHERE id = ${request.commCommunityID}
+    FOR UPDATE;
+
+    UPDATE communities
+    SET farcaster_channel_id = ${request.farcasterChannelID},
+      blob_holder = ${blobHolder}
+    WHERE id = ${request.commCommunityID};
+
+    COMMIT;
+
+    SELECT
+      @currentFarcasterChannelID AS oldFarcasterChannelID,
+      @currentBlobHolder AS oldBlobHolder;
+  `;
+
+  try {
+    const [transactionResult] = await dbQuery(query, {
+      multipleStatements: true,
+    });
+
+    const selectResult = transactionResult.pop();
+    const [{ oldFarcasterChannelID, oldBlobHolder }] = selectResult;
+
+    if (oldFarcasterChannelID && oldBlobHolder) {
+      await deleteBlob(
+        {
+          hash: farcasterChannelTagBlobHash(oldFarcasterChannelID),
+          holder: oldBlobHolder,
+        },
+        true,
+      );
+    }
+  } catch (error) {
+    await deleteBlob(
+      {
+        hash: farcasterChannelTagBlobHash(request.farcasterChannelID),
+        holder: blobHolder,
+      },
+      true,
+    );
+
+    if (error.errno === MYSQL_DUPLICATE_ENTRY_FOR_KEY_ERROR_CODE) {
+      throw new ServerError('already_in_use');
+    }
+    throw new ServerError('invalid_parameters');
+  }
+
   return {
-    commCommunityID,
-    blobHolder,
+    commCommunityID: request.commCommunityID,
+    farcasterChannelID: request.farcasterChannelID,
   };
 }
 
diff --git a/lib/actions/community-actions.js b/lib/actions/community-actions.js
--- a/lib/actions/community-actions.js
+++ b/lib/actions/community-actions.js
@@ -48,7 +48,7 @@
 
     return {
       commCommunityID: response.commCommunityID,
-      blobHolder: response.blobHolder,
+      farcasterChannelID: response.farcasterChannelID,
     };
   };
 
diff --git a/lib/types/community-types.js b/lib/types/community-types.js
--- a/lib/types/community-types.js
+++ b/lib/types/community-types.js
@@ -22,7 +22,7 @@
 
 export type CreateOrUpdateFarcasterChannelTagResponse = {
   +commCommunityID: string,
-  +blobHolder: string,
+  +farcasterChannelID: string,
 };
 
 export type DeleteFarcasterChannelTagRequest = {
diff --git a/lib/types/validators/farcaster-channel-tag-validators.js b/lib/types/validators/farcaster-channel-tag-validators.js
--- a/lib/types/validators/farcaster-channel-tag-validators.js
+++ b/lib/types/validators/farcaster-channel-tag-validators.js
@@ -8,5 +8,5 @@
 export const createOrUpdateFarcasterChannelTagResponseValidator: TInterface<CreateOrUpdateFarcasterChannelTagResponse> =
   tShape<CreateOrUpdateFarcasterChannelTagResponse>({
     commCommunityID: tID,
-    blobHolder: t.String,
+    farcasterChannelID: t.String,
   });