Voluntary UK Tax
Disclosures For Expats

A voluntary disclosure is where you proactively tell HMRC about UK tax that hasn't been declared or paid, before HMRC contacts you about it. This is typically needed if you've under-reported or failed to report income or gains — foreign income, rental income, or capital gains are common examples — whether the error was a genuine mistake, carelessness, or something more deliberate.

HMRC receives data from a wide range of sources, including UK banks and letting agents, overseas tax authorities under international exchange-of-information agreements, Land Registry records, and its own compliance software that cross-checks returns against other data it holds. It's increasingly common for HMRC to write to individuals directly ("nudge letters") once its data suggests a discrepancy, even before a formal enquiry begins.

Do not ignore it, and do not assume it means you owe tax. A nudge letter is not a formal investigation, but it means HMRC holds information suggesting a discrepancy, and it will usually set a deadline to respond. It is worth taking advice before replying, because your response can affect the penalties charged and may need to be followed by a formal disclosure.

This depends on why the tax wasn't paid in the first place. HMRC generally allows assessments going back 4 years for a genuine mistake, 6 years where the error was careless, and up to 20 years where the behaviour was deliberate. Because this materially affects both the tax and penalties involved, correctly categorising the behaviour for each year is one of the more important parts of preparing a disclosure.

You must only report income on your tax return if it was received in that year. Tax returns can be submitted up to four years after the end of the tax year and older income must therefore be disclosed separately, however a multi-year disclosure may be preferable to submitting multiple tax returns.

Historic foreign income is typically disclosed to HMRC through the Worldwide Disclosure Facility (WDF). You register your intention to disclose, which starts a 90 day window to calculate the UK tax, interest and penalties due, submit the disclosure and pay. Acting promptly matters because overseas tax authorities share information with HMRC, and foreign tax already paid may be creditable under UK double taxation relief.

Historic rental income is typically disclosed through the Let Property Campaign (LPC). You register with HMRC, then have 90 days to calculate the income, deduct allowable expenses, and pay the tax, interest and any penalty. Non-residents with UK property remain liable to UK tax on the rent, as explained in our guide to UK tax on rental income for non-residents.

The Digital Disclosure Service (DDS) is the online system HMRC uses to process most voluntary disclosures, and the Worldwide Disclosure Facility and Let Property Campaign are both accessed through it. In practice, which specific campaign or facility applies depends on the type of income involved, but the disclosure itself is typically submitted through the same DDS portal.

Where behaviour was deliberate, or HMRC suspects serious fraud, disclosures are usually handled through the Contractual Disclosure Facility (CDF, also known as Code of Practice 9) rather than the WDF or Let Property Campaign. This process offers protection from criminal prosecution for the tax matters disclosed, in exchange for making a full and accurate admission, but it's a formal process that's best entered into with professional advice.

A disclosure needs to show the income or gains that were not declared for each year, the tax due on them, and the reason the tax was not paid. You will typically need bank statements, rental records, foreign tax documents and details of any tax already paid overseas, so that the UK tax, any double taxation relief, interest and penalties can be calculated accurately.

If a disclosure is required, HMRC should be notified as soon as possible. After you register, you will typically have 90 days to disclose the relevant income and pay the associated tax. There is no fixed date by which you must volunteer, but once HMRC contacts you any disclosure is treated as prompted, which usually means higher penalties.

Penalties depend on the reason for the error and whether the disclosure is unprompted or prompted. They range from no penalty where reasonable care was taken, up to 30% for careless behaviour, 70% for deliberate behaviour and 100% for deliberate and concealed behaviour, with higher maximums (up to 200% in some cases) where offshore matters are involved. HMRC also charges interest from the date the tax should have been paid.

Yes. An unprompted disclosure — one made before HMRC has any reason to suspect an issue — generally attracts a significantly lower penalty than a prompted one made after HMRC has already been in touch or opened an enquiry. Acting early, before HMRC's own data catches up with you, is usually the single biggest factor in minimising the penalty charged.

HMRC may agree a payment arrangement in some cases if you cannot pay in full, but this needs to be raised with HMRC rather than assumed, and interest continues to build on unpaid amounts. It is best to discuss your options at the start, before the 90 day window closes.

HMRC reviews the disclosure and may ask follow-up questions. If it accepts the disclosure, it will confirm the tax, interest and any penalty due, and the matter is generally concluded for the years and income covered. If it is not satisfied, it can request further information or open an enquiry.

Yes. Leaving the UK does not remove UK tax that was due for earlier years, and non-residents remain taxable on UK-source income such as rent from UK property. HMRC can pursue undeclared tax after you have left, and it receives information from overseas authorities, so a disclosure can and should be made from abroad. If you left the UK recently, see our tax advice when leaving the UK.

It isn't a legal requirement, but disclosures involve calculating tax and interest across multiple years, correctly categorising the behaviour behind each error, and presenting the case to HMRC in a way that supports the lowest justifiable penalty. Given how much these judgement calls can affect the final amount owed, most people find professional support worthwhile, particularly for multi-year or higher-value disclosures. Book a consultation to discuss your position.