If you no longer need to file Self Assessment tax returns, you should tell HMRC.

If, after you have filed your tax return, you become aware that an entry is incorrect, you can amend that return if you are in time to do so. Also, if you have used provisional figures when you completed a tax return, you will need to amend your tax return when the actual information becomes ...

Self Assessment payments usually become due on 31 January each year. Sometimes payments are also due on 31 July too. Here we explain which Self Assessment tax payments are due on each of these days. 

If you were required to submit a Self Assessment tax return for a particular tax year to HMRC but you did not do so, HMRC may eventually send you a letter which sets out a ‘determination’ of the tax they think you owe for that tax year. If you failed to file more than one tax return you may get ...

A key part of Self Assessment is calculating your tax (and, if appropriate, self-employed National Insurance contributions and student loan repayments) due for the tax year. In most cases, HMRC perform this calculation for you based on the information you include on your tax return. 

If you do not have all the information you need to be able to complete your tax return accurately, you can use a provisional or estimated figure. If you do this, it means you do not need to delay submitting your tax return to HMRC and risk getting a late filing penalty.