Error: We were unable to authenticate with HMRC

While trying to switch on the MTD functionality in Sage or make an MTD VAT Return submission, the following message may appear:

This issue can occur as a result of one (or more) of the following:

  • The company VAT registration number you’ve entered in Sage isn’t linked to the Government Gateway user ID you authenticated with. To fix this, please enter the correct VAT number in More > Settings > Accounting Dates & VAT.
  • You’ve entered incorrect Government Gateway credentials when authenticating. Please check that the correct Government Gateway user ID and password have been used.