Last updated: 16 October 2026
What should you do if you haven’t filed tax returns for several years?
Act now, before HMRC contacts you. If HMRC sent you notices to file, file the missing returns as soon as possible, as penalties grow the longer they’re late. If you were never registered but had taxable income, tell HMRC through the Digital Disclosure Service and pay the tax, interest and a reduced penalty. Coming forward voluntarily means lower penalties than if HMRC finds you first. HMRC can usually go back 4 years for innocent mistakes, 6 for carelessness and up to 20 for deliberate behaviour.
Two situations
| Situation | What to do |
| HMRC issued notices to file | File the returns online (or on paper for older years) and pay |
| Never registered, income untaxed | Disclose through the Digital Disclosure Service |
| No tax due, but notices issued | File anyway to stop penalties, or ask HMRC to withdraw the notice |
Late filing penalties
- £100 immediately after the deadline
- £10 a day after 3 months, up to £900
- 5% of tax due (or £300 if more) after 6 months
- Another 5% or £300 after 12 months, more for deliberate withholding
- Late payment penalties and interest on top
A new points-based late filing system applies to MTD for Income Tax users from April 2026.
How to disclose
- Notify HMRC of your intention to disclose.
2. You get 90 days to calculate and pay.
3. Work out income, expenses and tax for each year.
4. Make the disclosure and payment.
5. Explain why the income wasn’t declared.
Example
Tom, a self-employed plasterer, stopped filing in 2020 after a family illness. HMRC has charged penalties for 2020/21 to 2023/24. He works with an accountant to file all four returns in 2026, showing tax of £8,000. He appeals some penalties on the basis of reasonable excuse, gets them reduced and agrees a Time to Pay arrangement.
Reasonable excuse
Serious illness, bereavement or a system failure can be a reasonable excuse for filing late. You must file as soon as the excuse ends.
Common mistakes
- Ignoring letters
- Assuming no tax is due so no return is needed
- Filing estimates without correcting them
- Not paying while filing
Records to keep
Keep bank statements, invoices, receipts and any correspondence with HMRC for each year.
Reconstructing missing records
If you no longer have full records, rebuild them from bank statements, customer emails, invoices held by clients and platform reports. HMRC accepts reasonable estimates where records are genuinely lost, as long as you explain how they were worked out and correct them if better information turns up. Keep your workings in case HMRC asks.
Frequently asked questions
Can HMRC estimate my tax?
Yes, through determinations, which stand until you file.
Can I go to prison?
Rarely, only for serious deliberate evasion.
How far back can I file online?
Online filing is available for the last few years; older ones need paper forms.
Will I lose my State Pension record?
Unpaid Class 2 years may be missing; consider voluntary contributions.
Getting help
An accountant can reconstruct missing records, prepare returns and negotiate with HMRC.
Related: a million taxpayers miss the deadline, late filing fines with no tax owed and struggling to pay your tax bill.
Talk to Accotax
Want this handled for you? Our team at Accotax can help with overdue tax returns help. See our self assessment accountants service, or contact us for a free, no-obligation quote.
This page is general guidance based on HMRC rules for the 2026/27 tax year, checked against gov.uk on 16 October 2026. It is not personal advice, so speak to an accountant about your own situation.
