My friend tried to sign up to a plan with Three today. They made a £1 charge on her Monzo card to verify her bank details, but she was told she would have to provide additional information (photo ID and bank statement) because the Auth Code on the reciept wasn’t all numbers (it was something like AEB51F). He said something about it not being a standard chip and pin card, or something along those lines.
She was still able to sign up fine by getting the statement off the app, but I was surprised that the Three employees appeared to be treating this differently to other cards. Thought I’d post the experience here to see if that was expected?