Should I file my 24/25 tax return before joining the voluntary MTD testing?

No, there is no need to file first. We suggest that you actually join the testing first, and then file - because some aspects of the filing could mean that you are prevented from signing up to MTD.

Once you are in Making Tax Digital, your future tax records move across to HMRC's new HMRC filing and record keeping system.

Your previous tax returns are held in HMRC's old system.

It means that once you are in MTD, you can still file your previous year under self assessment.

You can do this however you choose - including in untied.

In this case, let us know ... we have a switch that can move your filing connections from one HMRC system to the other.