I created a new ID — how come my contacts still see my old ID?

If you link your new Threema ID to the same phone number or email like the previous ID, your contacts might see your name twice. You can fix this as follows:

  1. Link your new ID with the same email address and phone number as your old ID. This will cause the link of the old ID to be removed, since every email address or phone number can only be linked to one ID at a time.
  2. Ask your chat partners to delete your old ID from their contact list. It will not be found during synchronization anymore as the links have been removed.
  3. If you were a member of group chats, please ask the respective administrators to remove your old ID and add the new one. If you were a group administrator yourself, the groups in question must be re-created or cloned by existing group members.

If you cannot or prefer not to create a new ID, you can also unlink your old ID.

Read here how you can get rid of duplicate contacts in your own address book.