This is either because the authorisation between the software and HMRC has expired (it typically lasts 18 months) or the incorrect HMRC credentials have been used to authorise the software.

To fix this you will need to reset your HMRC Authorisation, to do this:

1. Open and Login to the software
2. Select the cog icon at the top right
3. Select [Rest HMRC Authorisation]

After doing this try retrieving the periods or submitting the return again and you’ll be asked to authorise the software again, once this is complete you should be able to continue successfully.

A common mistake when authorising the software is users entering their personal HMRC credentials rather than those specifically issued for the business.