by Asim Abbas
11 November 2026 
HMRC voluntary disclosure: when and how to come forward
HMRC voluntary disclosure: when and how to come forward
If you’ve not declared income or gains to HMRC, whether from a side business, rental property, crypto or money abroad, coming forward yourself is almost always the best option.
- Coming forward before HMRC contacts you means lower penalties
- There are separate routes for UK income, rental income and offshore income
- HMRC can go back 4, 6, 12 or 20 years depending on behaviour
- You usually get 90 days to calculate and pay
Penalties are significantly lower for voluntary disclosures than when HMRC finds the problem first, and HMRC now receives more data than ever.
This guide explains when you need to disclose, the different routes and what the process looks like.
When you might need to disclose
- Self-employed or side-hustle income you didn’t declare
- Rental income from a UK or overseas property
- Crypto gains or staking income
- Interest, dividends or gains from overseas accounts
- The High Income Child Benefit Charge you didn’t pay
- A property sale where CGT wasn’t reported
Which disclosure route?
| Situation | Usual route |
|---|---|
| Undeclared UK income or gains | HMRC Digital Disclosure Service |
| Undeclared residential rental income | Let Property Campaign |
| Offshore income, gains or assets | Worldwide Disclosure Facility |
| Deliberate tax fraud | Contractual Disclosure Facility (COP9) |
How far back HMRC goes
- 4 years: mistakes despite taking reasonable care
- 6 years: careless errors
- 12 years: offshore matters, except deliberate
- 20 years: deliberate behaviour
Late tax return penalty calculator
See penalty and interest exposure.
How penalties work
Penalties are a percentage of the tax owed, and depend on why it happened, whether you came forward unprompted and how much help you give. An unprompted careless disclosure can attract a penalty as low as 0%, while a prompted deliberate one can reach 70% or more for UK matters and higher for offshore.
A landlord didn’t declare £6,000 a year of rent for five years. Unpaid tax is around £6,000 if they’re a basic rate taxpayer. Coming forward unprompted, with a careless behaviour finding, could mean a penalty close to 0%, plus interest. If HMRC found it first, the penalty could be up to 30%.
Fixed-fee accountancy support
Transparent monthly packages for sole traders, landlords and limited companies. Fixed fees agreed upfront, VAT included.
Get a fixed-fee quoteCall 0161 531 4179The disclosure process
- Notify HMRC that you want to make a disclosure
- You get a reference and usually 90 days to prepare it
- Work out the tax, interest and penalty for each year
- Submit the disclosure and pay, or agree a payment plan
If HMRC has already written to you
If you’ve had a nudge letter or a certificate of tax position request, act quickly and take advice before replying. See our guides on the HMRC letter about income abroad and HMRC’s disclosure opportunities. Our disclosure team handles the whole process confidentially.
What should I do next?
By year and income type.
UK, rental or offshore.
Unprompted means lower penalties.
Frequently Asked Questions
What happens if I make a voluntary disclosure?
You notify HMRC, then calculate and pay the tax, interest and penalty, usually within 90 days. Coming forward yourself normally means lower penalties.
How far back will HMRC go?
Four years for innocent errors, six for careless, 12 for offshore and 20 for deliberate behaviour.
Will I be prosecuted?
Prosecution is rare where people come forward voluntarily and make a full, accurate disclosure.
Can I pay in instalments?
Often yes. HMRC may agree a payment plan if you can’t pay everything at once.
Is the process confidential?
Yes. We deal directly with HMRC on your behalf and keep your information confidential.
Need help with this? Wingate Accountants offers fixed-fee online accountancy support across the UK. Call 0161 531 4179 or request a quote at wingateaccountants.co.uk.
About the Author
Stephen Reynold
I’m Stephen Reynold, an accountant at Wingate Accountants. I work with sole traders and small companies, turning tax rules into clear, practical next steps.
