This means that the number we hold on our records currently does not match the number you are using to register.
You will need to update your mobile number with us before you can complete your Paym registration.
This can be done by logging in to Online Banking at www.onlinebanking.natwest.com (opens in a new window) - you will require a card-reader to make this change
Once we have your correct mobile number you can register for Paym using the mobile banking app.