No More January Panic
The 31 January Self Assessment deadline doesn't have to be terrifying. Whether you've missed it, you're about to, or you want to make sure you never panic again — we've got you.
Self Assessment deadline — 31 January 2027
MTD quarterly update due in 53 days (7 November 2026) — Check if this applies to you
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Self Assessment: Your Questions Answered
When is the Self Assessment deadline?
The deadline to file your Self Assessment tax return online and pay any tax you owe is31 January each year. If you file on paper, the deadline is 31 October. Miss it and you'll face an automatic £100 penalty. See ourmissed deadline guide for what to do if you're already late.
What happens if I miss the Self Assessment deadline?
You get an automatic £100 penalty after one day, then £10 per day after three months (up to £900), plus further surcharges at 6 and 12 months. The full breakdown is in ourwhat happens when you file late guide.
How do I file my Self Assessment tax return?
You file online through your HMRC Government Gateway account, or you can use a filing service or accountant. Our complete Self Assessment guide walks you through every step, from registering to submitting.
Where can I get help with my Self Assessment?
You can DIY with our free guides, use an online filing service, or hire an accountant. Compare your options in our Self Assessment help section, or use our free accountant matching service.