Do I have to reply to an HMRC nudge letter?

A nudge letter is HMRC's way of flagging a data mismatch without opening a formal enquiry. It typically says HMRC holds information suggesting you may have undeclared income or gains, and invites you to check your position and correct it if needed.

Because it is not issued under a specific statutory power such as Schedule 36 Finance Act 2008, there is no legal deadline forcing a reply. That does not make it safe to bin. The letter exists because HMRC's systems have already matched your name against third-party data, and the case will not simply disappear.

Nudge letters usually form part of HMRC's One to Many campaigns, where a single letter is sent to a large group identified through data sources such as property records, exchange data, marketplace reporting or the Common Reporting Standard. There is no dedicated statute creating the letter; it is an administrative tool sitting alongside HMRC's general powers.

What the letter does affect is your penalty position under Schedule 24 Finance Act 2007. A disclosure made before HMRC formally contacts you about the specific issue counts as unprompted, attracting the lowest penalty range. Once you have received a nudge letter naming the issue, any subsequent disclosure is usually treated as prompted, with a higher penalty range for the same underlying error.

If you do not respond at all, HMRC's next step is often to open a formal enquiry into your Self Assessment return under the Taxes Management Act 1970, or in more serious cases to consider Code of Practice 8 or Code of Practice 9 procedures, which carry a formal information-gathering framework and greater cost.

Nudge letters are usually addressed to individuals about personal tax matters such as rental income, dividends, offshore accounts or online selling income, rather than to the company itself. As a director, check whether the letter concerns your personal Self Assessment position, your company's corporation tax return, or both.

If dividends or a director's loan account are involved, review company records alongside your personal return before replying, since HMRC can cross-check both once an enquiry starts.

Responding promptly and disclosing where needed usually keeps costs to the tax, interest and a modest penalty. Ignoring the letter and later facing a formal enquiry adds professional fees, a longer process and a higher penalty band for the same underlying error.

If a nudge letter develops into a formal enquiry, tax investigation insurance included with our Growth plans can cover professional representation costs — see /fees for details.

Do not assume the letter is a scam simply because it feels unexpected. Genuine nudge letters reference specific HMRC campaigns and give a named contact point; check details carefully rather than dismissing the letter outright.

Avoid replying with a blanket denial before checking your records properly. An inaccurate response can be worse than a considered, slightly later one.

Do not wait for a second letter. HMRC's One to Many campaigns often move straight to a formal enquiry after one unanswered nudge letter, removing your unprompted disclosure opportunity entirely.