Key Penalty Facts
- Automatic £100 penalty the day after 31 January
- £10/day after 3 months (up to £900)
- £300 or 5% at 6 months and again at 12 months
- Late payment: 5% surcharge at 30 days, 6 months, 12 months
Calculate Income Tax Penalty
Self Assessment Penalty Schedule
| Trigger Point | Penalty |
|---|---|
| 1 day late (after 31 Jan) | £100 automatic penalty |
| 3 months+ late | £10/day for up to 90 days (£900 max) |
| 6 months+ late | £300 or 5% of tax due (whichever higher) |
| 12 months+ late | Further £300 or 5% of tax due |
| 30 days after payment due | 5% surcharge on unpaid tax |
| 6 months after payment due | Further 5% surcharge |
| 12 months after payment due | Further 5% surcharge |
Frequently Asked Questions
What is the penalty for late Self Assessment filing?
An automatic £100 penalty applies the day after 31 January. After 3 months, £10/day for up to 90 days (£900 max). After 6 months, £300 or 5% of tax due (whichever is higher). After 12 months, the same again.
What is the penalty for paying income tax late?
5% surcharge on unpaid tax after 30 days, another 5% after 6 months, and another 5% after 12 months. Late payment interest at Bank Rate + 2.5% also applies daily.
Can I appeal an income tax penalty?
Yes, within 30 days of the penalty notice. Reasonable excuses include serious illness, bereavement, or documented IT failures. Submit appeals through your Self Assessment account or by post.
What counts as a reasonable excuse?
Serious illness, death of a close relative near the deadline, a flood or fire destroying records, or documented HMRC system failures. Forgetting or inability to pay are not accepted excuses.
What is the Self Assessment deadline?
Online returns: 31 January following the tax year end. Paper returns: 31 October. For 2024/25 the online deadline is 31 January 2026.
Do I still owe £100 if I have no tax to pay?
Yes. The £100 automatic penalty applies even if no tax is owed, though HMRC has discretion to cancel it in nil-tax cases on appeal. It is always better to file on time.
Is there a maximum late filing penalty?
In extreme cases, up to 100% of tax due for deliberate failures after 12 months. For most filers: £100 + up to £900 daily + two rounds of £300/5% surcharges.
Are penalties charged on top of tax owed?
Yes. Penalties and interest are additional to the tax liability. Paying the tax stops further surcharges but does not cancel penalties already incurred.
What is late payment interest?
Bank Rate + 2.5% per annum, calculated daily from 1 February (for the 31 January payment deadline) until full payment.
Can HMRC collect through my PAYE code?
Yes, for amounts up to around £3,000. HMRC can adjust your PAYE code to collect the debt over the following tax year via reduced take-home pay.
What if I cannot afford to pay?
Contact HMRC on 0300 200 3822 to arrange a Time to Pay agreement before enforcement begins. A TTP stops further surcharges accruing.
What is an inaccuracy penalty?
Inaccuracy penalties: careless up to 30%, deliberate up to 70%, deliberate and concealed up to 100% of potential lost revenue. Unprompted disclosures attract lower rates.