HMRC Investigation Rights
Written in plain language for general understanding. This is educational content, not legal advice. Based on UK Acts of Parliament, statutory instruments, and official guidance.
UK National Law
What is this right?
HMRC can open an enquiry (investigation) into your tax return to check if it's accurate. There are two types:
- Aspect enquiry: HMRC checks a specific part of your return (e.g., one expense claim).
- Full enquiry: HMRC examines your entire return and financial affairs.
HMRC must open an enquiry within 12 months of the filing date (the date you submitted, or the deadline, whichever is later). After this window closes, they can only go back further if they discover a deliberate or careless error:
- Careless errors: HMRC can go back 6 years
- Deliberate errors: HMRC can go back 20 years
When does it apply?
- HMRC may select your return randomly or because something looks unusual (a sudden drop in income, unusually high expenses, information from third parties).
- You'll receive a formal notice telling you an enquiry has been opened.
- You have the right to ask HMRC to close the enquiry if it's been going on too long — if they refuse, you can apply to the tribunal.
- HMRC can issue information notices requiring you to produce documents — these are legally enforceable.
What should you do?
- Don't panic — many enquiries result in no additional tax being due.
- Get professional help — consider an accountant or tax adviser who is experienced with HMRC enquiries. If you have tax investigation insurance, notify your insurer.
- Respond promptly and provide the documents HMRC asks for — unreasonable delay can increase penalties.
- You have the right to appeal any assessment you disagree with — first to HMRC, then to the First-tier Tribunal (Tax).
- If you've made a genuine mistake, tell HMRC — making a voluntary disclosure significantly reduces penalties.
What should you NOT do?
- Don't ignore HMRC correspondence — this can lead to estimated assessments and additional penalties.
- Don't destroy records — this is a criminal offence if done to frustrate an investigation.
- Don't lie or provide false documents — this turns a civil matter into a potential criminal prosecution.
Legal Resources
We may earn a commission if you use these services — at no extra cost to you. This supports our mission to make legal information free for everyone.