Missing a tax deadline can result in penalties from HMRC, but a taxpayer may be able to appeal if they have a genuine reasonable excuse. Whether an excuse is accepted depends on the individual facts and whether the taxpayer took action to put things right without unnecessary delay.

HMRC does not provide a complete list of acceptable excuses, as each case is considered on its own facts. However, examples that may qualify include serious illness, bereavement, unexpected events outside the taxpayer’s control, or problems with HMRC’s systems that prevented a return or payment being made on time.

Other situations may also be accepted where the taxpayer can demonstrate that circumstances prevented them from meeting the deadline and that they took action to put matters right without unreasonable delay once those circumstances ended. For example, a taxpayer may have experienced an unexpected failure of computer equipment or lost essential records due to circumstances beyond their control.

A reasonable excuse will generally not include situations such as forgetting a deadline, relying on another person who failed to complete the task, or not having enough money to pay a tax bill unless the financial difficulty was caused by an exceptional circumstance.

If HMRC accepts that there was a reasonable excuse, the penalty may be cancelled. Taxpayers should appeal promptly, normally within 30 days of the date on the penalty notice, and explain what happened, when it occurred and why it prevented them from meeting their obligation.

Keeping good records and contacting HMRC as soon as a problem arises can help demonstrate that reasonable steps were taken to meet tax responsibilities.