Im dealing with the following use case for 3 different users on a single shared device:

  1. User A installs the app and logs into the app
  2. User A logs out
  3. User B starts using the app in guest mode without logging in
  4. User C logs into the app Can someone explains how does contact key registration work for this specific use case if Im not using delay and want to include users that are not logged in as target for push notifications?

Couple of specific questions:

Will I have to set the anonymous UUID as the Contact Key when the user logs out every time? And does this mean we will go back to the same setting for guest mode every time we log out?

When User A logs out will its contact key become orphaned or it will be replaced by the anonymous UUID of User B (which is not logged in)? What happens when user C logs in?

When User A logs out and user B logs in, will the contact key of user A become orphaned or will it be replaced with the new contact key for user B?

Will the second user get a new contact key when logs into the same shared device with his own specific settings for notifications?

1 Answer 1


Multiple users on a single device is not a supported use-case with SFMC Push. SDK does not handle the login/logout scenarios. Since the deviceId would be static for the installation, Setting the multiple contact keys(anonymous, or actual) for the same deviceId might result in unexpected behaviours.

  • Hi! Thanks for the response! The anonymous UUID is the suggested approach for the login/logout use case: salesforce.stackexchange.com/questions/320636/… How can this cause issues since the anonymous UUID will be replaced by the actual contact key when the user registers into the app
    – SFguy
    May 17, 2023 at 16:26
  • That is a simple solution that we can use to handle login and logout requirements. It can handle most situations. When a message is sent to contact key A, and the user then logs out, you can set an anonymous key XYZ. The anonymous user will still be able to see messages for contact key A in their inbox. May 19, 2023 at 4:42

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .