Forbidden: MTD authorisation not found

Scenario

You may see the following or similar message when you try to authorise your firm for MTD for VAT.
Error message
<?xml version="1.0" encoding="ISO-8859-1"?> <HMRCError xmlns="http://schemas.datacontract.org/2004/07/BlueMoon.UKHMRC.Models" xmlns:i="http://www.w3.org/2001/XMLSchema-instance"> <Code>Forbidden_MtdAuthoristationNotFound</Code> <Errors i:nil="true"/> <Message>Data is out of date; probably updated or deleted by another user. Refresh the page and try again.</Message> </HMRCError>

Cause

The error is not caused by Onvio. It is most likely to be caused by a problem at HMRC.

Solution

You will need to contact HMRC VAT Online Services Help Desk to solve the problem.