63103: Cannot assign payment method to WABA provided

This error occurs when Twilio cannot assign your WhatsApp Business Account (WABA) to Twilio's credit line during sender registration. Meta only allows a payment method on a WABA to be revoked, not fully removed. If you already use WhatsApp with another provider, create a new WABA to use with Twilio instead of selecting a WABA that was created outside of Twilio.

• You selected a WABA that is already assigned to another payment method.
• You selected a WABA that has been used with another provider or was created outside of Twilio.
• You selected a different Meta Business Portfolio or a different WABA than the one already connected to this Twilio account when adding another sender. Twilio requires all WhatsApp senders in one account to use the same WABA.
• Meta's credit line assignment service is temporarily unavailable.

• If you are registering your first sender or moving from another provider, select your existing Meta Business Portfolio and create a new WABA in Twilio during Self Sign-up or Embedded Signup.
• If you are adding another sender to the same Twilio account, select the same WABA that you used for your first WhatsApp sender.
• Wait a few minutes and retry the request if the failure appears temporary.
• If the error continues, contact Twilio Support.

• Register WhatsApp senders using Self Sign-up
• Migrate phone numbers and WhatsApp senders
• Using WhatsApp Business Accounts with Twilio