Self Assessment deadlines and penalties for the self-employed

The dates

• 5 October: register for Self Assessment if you started self-employment in the tax year that ended on 5 April
• 31 October: paper tax return deadline
• 31 January: online tax return deadline, and pay the year's bill plus your first payment on account
• 31 July: second payment on account

Filing late

• £100 straight away, even if there's no tax to pay
• After 3 months: £10 a day, up to £900
• After 6 months: a further 5% of the tax due or £300, whichever is more
• After 12 months: another 5% or £300, whichever is more

Paying late

Penalties of 5% of the tax unpaid at 30 days, 6 months and 12 months. On top of that, HMRC charges interest on everything paid late, at the Bank of England base rate plus 4%.

Under Making Tax Digital

Once you're in Making Tax Digital for Income Tax, a points system replaces these penalties. Each missed deadline earns a point, and at 4 points you get a £200 penalty, then £200 for each later miss. There are no penalties for late quarterly updates in 2026/27. Late payment penalties start at 3% of the tax owed after 15 days (30 days in your first year), rising to 4% from 2027/28. From April 2027 the new penalties apply to everyone who sends a personal tax return.

If you can't pay

File on time anyway, as that avoids the filing penalties. Then call HMRC or set up a Time to Pay plan online before the deadline: you can usually spread a bill of up to £30,000 into monthly payments. Interest still runs, but the late payment penalties can be avoided.

Reasonable excuse

If something serious stopped you, such as a stay in hospital or a bereavement, you can appeal a penalty within 30 days. Being busy or forgetting doesn't count.