What this letter usually means
A compliance check, sometimes called an enquiry, is HMRC looking more closely at a tax return or your records to check that the right amount of tax has been paid. It can cover a Self Assessment return, a company return, VAT, PAYE or other taxes. The letter will usually tell you which tax and which period it relates to, and what information HMRC would like to see.
It is important to understand that a check is not an accusation. Some checks are chosen at random. Many are risk based, which means something in the figures or in the data HMRC hold has prompted a closer look. That could be as simple as a figure that looks unusual compared with similar businesses, a large change from one year to the next, or information from a third party. In a great many cases, once the position is explained, HMRC accept the return as filed.
The single most helpful mindset is to treat the letter as a request for information rather than a verdict. Respond on time, be accurate, and keep your tone calm and cooperative. That approach, more than anything else, tends to lead to a smoother outcome.
Who it affects
Anyone within the UK tax system can receive a compliance check. That includes the self employed and sole traders, landlords, company directors, partnerships, and people who file Self Assessment returns alongside employment income. You can read more about how returns work on our Self Assessment guide.
Checks are more likely where there is more room for error or judgement. A sole trader claiming a wide range of expenses, a landlord with several properties, or a business with cash takings may attract attention simply because the figures involve more moving parts. It does not mean HMRC believe anything is wrong. It means there is more to confirm.
If you have an accountant or tax adviser, HMRC will often write to them as well as, or instead of, you. If you do not yet have representation, you are entitled to appoint someone at any point during the check, including right at the start.
What you must not ignore
The one thing you must not do is ignore the letter. A compliance check carries time limits, and HMRC can ask for documents and information through a formal information notice. These notices usually give you around 30 days to respond. Missing the deadline can lead to penalties for failing to comply, and it can make HMRC less willing to take a flexible view later.
If you cannot meet a deadline, the answer is not silence. HMRC will often agree a short, reasonable extension if you ask in good time and explain why. What causes problems is letting the date pass with no contact at all.
You also have rights that you must not overlook. You have the right to be represented by an accountant or adviser, the right to understand why information is being requested, and the right to appeal certain decisions, including some information notices and the penalties that can follow. Knowing these rights early helps you respond with confidence rather than worry.
What you may need to gather
The exact documents depend on the tax and period under check, but it helps to start pulling things together early so you are not rushed. Common items include:
- Bank statements for the relevant period, both business and sometimes personal
- Sales records, invoices and receipts
- Records of expenses you have claimed, with the supporting paperwork
- Your bookkeeping records or accounting software exports
- Mileage logs, or records of any use of home as office
- Copies of the tax returns and computations in question
Good records make a check far easier. If your bookkeeping has slipped, this is a useful moment to bring it up to date. Our pages on bookkeeping and allowable expenses explain what good records look like and which costs you can legitimately claim. The clearer your paperwork, the quicker HMRC can satisfy themselves that the figures are right.
What to do, step by step
Taking the check one calm step at a time keeps it manageable.
- Read the letter carefully. Note which tax and period it covers, what is being asked for, and the deadline.
- Do not panic and do not ignore it. A measured response on time is what matters most.
- Get representation early. Speak to an accountant before you reply, especially before sending documents or explanations.
- Gather your records. Pull together the items above so you can respond fully and accurately.
- Respond by the deadline, or ask in good time for a reasonable extension if you genuinely need one.
- Answer only what is asked. Be honest and complete, but you do not need to volunteer unrelated material.
- Keep copies of everything you send and receive, and note the dates.
If the check shows extra tax is due, do not assume the worst about penalties. They depend on the nature of the error, and there is often scope to reduce them through full cooperation and disclosure.
A worked example
A sole trader receives a check into one year
Priya runs a small design business as a sole trader. She receives a letter opening a compliance check into one year of her Self Assessment, with HMRC questioning the level of expenses claimed against her income. The deadline to provide records is around 30 days away. Her first reaction is alarm.
Priya speaks to an accountant before replying. Together they review the year in question and find that the expenses were genuine but had been recorded in a slightly muddled way, with some personal and business costs mixed together in the bank statements. The accountant separates the business expenses clearly, matches each to a receipt, and prepares a tidy summary.
Because Priya is represented, the accountant deals with HMRC directly, responds within the deadline, and explains the figures professionally. A couple of small items turn out not to be allowable, leading to a modest amount of extra tax. As the error was careless rather than deliberate, and Priya cooperated fully and the disclosure was made promptly once the issue was found, the penalty is kept to the low end of the range. The check is closed without further dispute. Being represented turned a worrying letter into a manageable process.
When to speak to an accountant
The best time to speak to an accountant about a compliance check is before you reply to the letter. What you say and send at the start shapes how the whole check unfolds, and an experienced adviser can help you respond accurately, meet the deadlines, and present your records in the clearest light.
An accountant can deal with HMRC on your behalf, explain technical points, challenge requests that go beyond what is reasonable, and help you appeal where you have grounds. If extra tax does turn out to be due, they can help argue for the lowest appropriate penalty. Looking ahead, our tax planning guide shows how good habits reduce the chance of future checks.
If you have received a compliance check letter, you do not have to face it alone. You can book a call with us, or get a fixed fee quote so you know where you stand from the outset.
A clear, calm guide to HMRC compliance checks and enquiries, your rights, the deadlines, and how to handle the letter well.