Help with HMRC compliance checks, enquiries and penalty appeals

In short: if HMRC has written to you about a compliance check, an enquiry into your tax return or a penalty, do not ignore it. AF Coopers & Co, ACCA Chartered Certified Accountants in Woodford Green, London, can deal with HMRC on your behalf: we review what HMRC is asking for, prepare the schedules and reconciliations, reply for you and, where a penalty is wrong, appeal it.

How we help

• Read the letter with you and explain what HMRC is asking and by when
• Get your authority so HMRC deals with us directly
• Review your records and returns, and spot problems before HMRC does
• Prepare the information, schedules and reconciliations HMRC asks for
• Correspond with HMRC and attend meetings with you
• Help you tell HMRC about any mistake in the right way, which can reduce penalties
• Appeal penalties and decisions that are wrong, or ask for a review

What a compliance check is

A compliance check is HMRC checking your tax position to make sure you are paying the right amount of tax at the right time and getting the right allowances and reliefs. HMRC will write or phone to say what they want to check. It can cover Income Tax, Corporation Tax, VAT, PAYE, Capital Gains Tax and other taxes.

You have the right to be represented, and you can ask HMRC for more time if you need it. You cannot ignore an information or inspection notice: if you do not provide what is asked, HMRC may use its legal powers to get it. At the end of the check HMRC sends a decision or agrees a settlement with you. If you owe tax, you usually have 30 days to pay it, plus interest.

For a Self Assessment return filed on time, HMRC can normally open an enquiry up to 12 months after the date the return was delivered.

Penalties for mistakes in a return

There is no penalty if you took reasonable care. If HMRC finds a careless or deliberate mistake, the penalty is a percentage of the extra tax due. It is lower if you told HMRC before they found it (unprompted).

Within each range, HMRC reduces the penalty for the quality of your disclosure: telling them, helping them and giving them access to your records. HMRC can also suspend a careless penalty for up to 2 years if you meet conditions they set.

Appealing a penalty

You usually have 30 days from the date a penalty was issued to appeal. You may be able to have it cancelled if you had a reasonable excuse, such as a serious illness or the death of a close relative shortly before the deadline. If HMRC does not change its decision, you can ask for a review or take your appeal to the tax tribunal. Read our guide: how to appeal an HMRC penalty.

VAT penalties

For VAT, a late return earns a penalty point. Quarterly filers get a £200 penalty when they reach 4 points, and a further £200 for each late return after that. Paying late brings separate penalties from day 16 and interest from the first day. See our VAT returns service.

Where we will send you to a specialist

If HMRC suspects fraud, for example under Code of Practice 9, or a criminal investigation is possible, you need specialist advice straight away. We will tell you honestly if your case needs it.

Sources: gov.uk, Tax compliance checks; About compliance checks (CC/FS1a); Penalties for inaccuracies in returns or documents (CC/FS7a); Disagree with a tax decision or penalty; Penalty points and penalties if you submit your VAT Return late; How late payment penalties work if you pay VAT late; HMRC Self Assessment Manual SAM31100. Checked 6 October 2026.

Who will do the work

Common questions

HMRC has written to say they are checking my tax return. What should I do?

Do not ignore it. Note the deadline in the letter, gather the records they ask for and get advice before you reply. You have the right to be represented, and we can deal with HMRC for you once you authorise us.

How long does HMRC have to start checking my Self Assessment return?

For a return filed on time, HMRC can normally open an enquiry up to 12 months after the date the return was delivered. The window is different for returns filed late or amended.

Will I get a penalty?

Not if you took reasonable care. If HMRC finds an inaccuracy that was careless or deliberate, the penalty is a percentage of the extra tax, and it is reduced for telling HMRC, helping them and giving access to records.

How long do I have to appeal a penalty?

You usually have 30 days from the date the penalty was issued. If you are late, you need to give a reason for the delay.

What does your help cost?

It depends on what HMRC is asking for and how much work is involved. For existing clients, some help with HMRC queries may be included in your package. We confirm the fee in writing before we start.

Do you deal with HMRC fraud investigations?

If HMRC suspects fraud, for example under Code of Practice 9, you need specialist advice straight away. We will tell you if your case needs a specialist.

General information only, not personal advice. Tax rules, rates and thresholds change, so please check gov.uk or speak to us about your own situation.