It is a fundamental part of the self assessment system that responsibility lies with you, the taxpayer, to file tax returns and pay the correct amount of tax, and before the payment deadline - you must not wait for HMRC to ask.
It is a fundamental part of the self assessment system that responsibility lies with you, the taxpayer, to file tax returns and pay the correct amount of tax, and before the payment deadline - you must not wait for HMRC to ask.