What happens if I file my tax return late?

HMRC charges penalties that stack up the longer you leave it:

• Day after the deadline: automatic £100 penalty, regardless of whether you owe any tax
• After 3 months: £10 per day for up to 90 days (up to £900)
• After 6 months: 5% of the tax due or £300, whichever is higher
• After 12 months: a further 5% or £300

Interest is also charged on any unpaid tax.

The key thing: filing as soon as possible stops the daily charges. If you can't pay the bill, file anyway — that limits penalties to the late payment side only. You can then contact HMRC about a Time to Pay arrangement to spread the cost.

We can help you file even if you're already late — just message us on live chat.