You cannot add the same phone number to more than one bank account at a time in Wero. If you want to link your phone number to your account in the Wero app, you must first remove it from the account it is linked to and then link it to your new account in Wero.
If your number is linked to a bank that does not support Wero in the Wero app, contact your bank to remove it.
To remove your number from an account in the Wero app, open the Wero app, go to Accounts, select the account and change/delete the phone number connected to that account. You can also reach out to Wero support via the chat in the Settings to delete your phone number.