The most common issue when connecting to HMRC is no MTD registration. To start filing your VAT return under MTD, you will first need to register for MTD with HMRC. You can do this for free, but after your registration it may take up to 72h before your account has been updated. Please allow some time after registering for MTD before trying to connect HMRC to your ANNA account.

Something to help troubleshoot common error codes that come up, maybe also include that it may take a few days to complete MTD registration HMRC side.

Blog article for how to register for MTD from Mahum: How to Register with HMRC for MTD

Did this answer your question?