FCM getting MismatchSenderId

I have an application that uses Google FCM for sending push notifications.

When i send a push notification to a group of users, i get a response of MismatchSenderId for some of them. Even though, all users have the exact same application. How can some of the users get a success response and others get a MismatchSenderId?

I have researched a lot and made sure I have added all prerequisites that FCM needs.

Any suggestions?


Sample response:



Here is the server side sending code (PHP):

$fields = array
  'to' => $token,
  'data' => $data

$headers = array
  'Authorization: key=AIza**************************',
  'Content-Type: application/json'

$ch = curl_init();
curl_setopt( $ch,CURLOPT_URL, 'https://fcm.googleapis.com/fcm/send' );
curl_setopt( $ch,CURLOPT_POST, true );
curl_setopt( $ch,CURLOPT_HTTPHEADER, $headers );
curl_setopt( $ch,CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch,CURLOPT_SSL_VERIFYPEER, true );
curl_setopt( $ch,CURLOPT_POSTFIELDS, json_encode($fields) );
curl_exec( $ch );
curl_close( $ch );


It seems that the issue has been resolved with the SDK updates. I am using now the latest com.google.firebase:firebase-messaging:9.6.1, I don't get "MismatchSenderId" anymore.


Firebase has upgraded their server keys to new version. Use new keys instead of old one.

go to settings->project settings->cloud messaging tab

Maybe it will work

I had the same problem. After hours spending to figure it out, I found this solution:

  • First I check server key is correct or not it was correct which is like AIzaXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
  • Then I check Sender Id like 79XXXXXXXX it was also correct.
  • Main issue was in device_ID(UDID) to whom I have to send the notification. Actually DeviceId we got on android side in FCM is different than GCM. You can't use GCM created DeviceId in FCM.

Hope this will help you. Thanks



I was using Server key from a different firebase project(say Project 2). I used the same server key as linked with my android project(Say Project 1) and it worked. In my experience, using one firebase app for one entire android project seemed to fix the problem.

In my case, I just was mistaking about project credentials: using google-services.json from one project, and server key from another.

what works for me : I found that the senderId is different from the project number in the FCM console so I re-downloaded google-services.json and everything works fine

Make sure you remove all the Parse code from your app (libraries, receivers in AndroidManifest, etc). I found that intermittently push notifications were not working. From my observations, it would work on fresh installs but not app updates from the play store.

I believe something internal to Parse was conflicting with FCM (Parse uses GCM, so I'm guessing it had to do with using GCM and FCM simultaneously). As soon as I ripped out all the Parse receivers and libraries, things worked great.

We spent hours and hours to resolve this issue. What we found that token was being generated using different FCM account settings (google-services.json) and notification was being set using different FCM account. When we synced both it worked like a charm.

check gcm_sender_id in manifest.json If mismatch - correct, but you need make new subscribers for new sender Id. Exists subscribers break.

As per response "MismatchSenderId", this is a mismatch between FireBase and your local "google-services.json", you have to make sure that both manifests matches

In FireBase console you go to "YourProject > Project OverView > Cloud Messaging" you'll see the "SenderID" which MUST match with the "google-services.json" in your Android project.

Best thing you can do is download the final json file from "General" tab and place it in your project.

I had the same error while trying to send push notificaion. Get the updated google-services.json file and replaced with it. Worked for me.

Actually there are many reasons for this issue. Mine was because of Invalid token passed. I was passing same token generated from one app and using same token in another app. Once token updated , it work for me.

Just an FYI. I was running into this error, even though I swear the android app I was testing was built with the latest/greatest google-services.json file and I could send from the FCM console to the app. I rebuilt the app after doing a Clean Project and now I can send to the app with the FCM token it registers. So, maybe try a clean rebuild before beating your head against the wall for too long.

I had the same problem, and I fixed it like this:

  1. Go to your google fcm console
  2. Select your app
  3. In the left side menu find settings icon (standard wheel)
  4. Click on it and after click on project settings
  5. Now copy your server key and paste it in php


Updating firebase initialization works for me..

<script src="https://www.gstatic.com/firebasejs/4.6.2/firebase.js"></script>
  // Initialize Firebase
  // TODO: Replace with your project's customized code snippet
  var config = {
    apiKey: "<API_KEY>",
    authDomain: "<PROJECT_ID>.firebaseapp.com",
    databaseURL: "https://<DATABASE_NAME>.firebaseio.com",
    storageBucket: "<BUCKET>.appspot.com",
    messagingSenderId: "<SENDER_ID>",

For me the problem was that I was using the phonegap-plugin-push in cordova, testing the app with the phonegap app.

The problem with this is that for some reason with this plugin, the phonegap app intercepts it and returns a dummy registration key, no matter what sender ID you have.

So to make it work (as long as you have all your keys right) is to test your program some other way, with an emulator, or android emulation via usb. And your keys will match.

Hopefully this saves someone some time.

your probably doing whwat i was doing. GCM token is not the same as FCM anymore. check if your pulling the GCM token ID instead of FCM. just override FirebaseInstanceIdService & ensure your getting the right ID. i thought at one point they were the same but now there not. i logged a test and saw. after you do that also update google-services.json like others say as a safety.

Hello i have noticed that when an device id is created in GCM you cannot send push messages through FCM using the new server key, you have to use the old API-key.

I wasted days on this.

In my case, I followed this blog to use Postman and get the mismatchsenderid error. Previously, I was getting messaging/mismatched-credential, and people reported that their client app used multiple projects.

However, for me, I have one-to-one, a web app and a project. BUT, I host all apps via ng serve on default port 4200. So regardless of what project / app pair I was developing on, I would always get the same token from my client web app using AngularFireMessaging.requestToken - this token was always the token created on my first ever run of a firebase app in development.

As a work around, I start different apps / projects on different ports and get proper tokens for respective projects.

Had big trouble figuring out why I was getting a "MismatchSenderId" status. I added the gms dependency in the root build.gradle but my error was actually not applying the gms plugin in the app build.gradle.

If you have don't have this line in the app build.gradle, this could be the reason why the notification are not working: apply plugin: 'com.google.gms.google-services'

Maybe this can help someone Cheers

You will have a server key something like this AIzaSyDiTEVq4Li1pj7IyraRlyRU9adc-49-KVY available in the Settings section of firebase console console.firebase.google.com/project/project-XXXXXXXXXXXXX/settings/cloudmessaging.

Specify the correct key with your code and try again.

I also getting the same error. i have copied the api_key and change into google_services.json. after that it workig for me

"api_key": [
          "current_key": "********************"

try this

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