If you have told HMRC that you are self-employed then it doesn’t matter if you worked one day or even no days as self-employed. As far as HMRC are concerned you are registered as self-employed and they will not have visibility of the actual hours/days you work.

As someone who is self-employed it is your responsibility to keep HMRC updated of your working status and earnings throughout the tax year. This is done by submitting your self-assessment tax return. Failure to submit a self-assessment tax return can lead to HMRC fining you which could amount to £1000s. For support with your tax return please email taxreturn@tax2u.co.uk