Compliance check · CC/FS1a · section 9A
HMRC compliance check or enquiry letter
For a letter saying HMRC is checking a return or a claim, including an enquiry into a Self Assessment return. This page gives HMRC's own factsheet and the law, with each source and the date it was checked.
Last reviewed 8 October 2026 · How Tax Letters checks its facts
The short answer
- What this letter is
- HMRC is checking a return or a claim. HMRC's factsheet CC/FS1a says a compliance check lets HMRC check your tax position to make sure you are paying the right amount of tax at the right time and getting the right allowances and tax reliefs. [1]
- Is it a finding?
- A check on its own is not a finding that anything is wrong. CC/FS1a says that if HMRC finds something wrong it will explain why and work with you to put it right, and that if HMRC owes you money it will normally refund it or credit your account. [1]
- The dates
- The date printed on your letter is HMRC's request. CC/FS1a asks you to tell HMRC if you need more time to do something it has asked, and says HMRC may agree extra time if there is a good reason, for example if you are seriously ill or someone close to you has died. [1]
- Your rights at a glance
Every fact on this page comes from a source listed at the foot of the page, with the date it was last checked. All sources and dates
The dates
This page starts no clock of its own. Every date here is the one printed on your letter.
If the letter says it is an enquiry into a return
A question to check, not a finding about your letter: when was the return sent, and was it sent on time, late or amended? Section 9A of the Taxes Management Act 1970 says HMRC can give notice of an enquiry into a return delivered on or before the filing date up to the end of twelve months after the day the return was delivered. For a return delivered after the filing date, or amended, section 9A allows until the quarter day after the first anniversary of the day the return was delivered or the amendment made. The quarter days are 31 January, 30 April, 31 July and 31 October. [2]
What HMRC can ask, and your rights
From HMRC's factsheet about compliance checks:
- CC/FS1a says HMRC may ask you to send information or documents, to have a meeting about your tax affairs and records, or to let it visit and inspect your business premises, assets and records.
- You can speak to the officer dealing with the check if you are not sure why something is being asked for, cannot do what is asked, or think a request is unreasonable or not relevant to the check.
- CC/FS1a says you have the right to be represented: you can appoint anyone to act on your behalf, such as a professional adviser, friend or relative, though HMRC may still need to contact you directly about some things.
- CC/FS1a asks you to continue to send returns and make payments that are due during the compliance check.
- CC/FS1a says that if you think you may have problems paying, you tell the officer dealing with the check straightaway.
- If you think HMRC should stop the check, CC/FS1a says you first need to tell HMRC why; if it does not agree, you may be able to ask the independent tribunal that deals with tax matters to decide if it should stop.
- If you are not happy with HMRC's service, CC/FS1a says to tell the person or office you have been dealing with; if you are still not happy, they will tell you how to make a formal complaint.
- CC/FS1a says that when HMRC has completed the check it will either send you one or more decision notices, such as an assessment, a penalty notice if a penalty is due, or a letter explaining the final position, or agree a contract settlement with you.
CC/FS1a says that if HMRC considers a penalty, it looks at how much you told it, helped it and gave it access during the check, which it calls the quality of disclosure. [1]
CC/FS1a says that if HMRC makes a decision you can appeal against, it will write to tell you what to do if you disagree. You will usually have three options: send new information to the officer, have the case reviewed by an HMRC officer not involved in it, or ask an independent tribunal to hear your appeal. You must do this within 30 days of HMRC's letter. [1]
CC/FS1a says you may also be able to ask for an HMRC specialist officer to act as a neutral facilitator to help resolve a dispute, which HMRC calls Alternative Dispute Resolution (ADR). It says ADR is only available for disputes in particular tax areas, and that the officer dealing with the check will tell you if it is available for your dispute. GOV.UK says alternative dispute resolution can be used during a compliance check where progress in the enquiry has stalled, and that it does not affect your right to appeal or to ask for a statutory review. It is not a statutory process, and HMRC can reject applications it does not consider appropriate. GOV.UK: use alternative dispute resolution to settle a tax dispute [1] [3]
The full factsheet: GOV.UK: About compliance checks [1]
If the letter says it is an enquiry into a return
Section 28A of the Taxes Management Act 1970 says an enquiry into a return is completed when an officer gives a closure notice stating their conclusions, and that the taxpayer may apply to the tribunal for a direction requiring HMRC to give a closure notice within a specified period. [4]
If one of these is you
Your health or circumstances make this hard
GOV.UK's extra support guide says that if you have been contacted about a compliance check, you need to contact your compliance officer for support, and that their contact details are in the letter. [5]
You need more time
GOV.UK says that if you need more time because of your circumstances and you have been contacted about a compliance check, you contact your compliance officer to ask for more time. [6]
HMRC has asked for a meeting
CC/FS1a says that if HMRC asks you to have a meeting it will explain why, and you can choose whether to have the meeting or not. HMRC will only ask to visit your home if you run your business from there. [1]
You get benefits, fees or grants based on your income
CC/FS1a says that if you get benefits, fees or grants based on your income and your income changes as a result of the check, you will need to tell the organisation that pays you. [1]
Get help early
If you talk to an adviser, these questions keep the conversation on your letter:
- What is HMRC checking, and which years and taxes does it cover?
- Is everything the letter asks for relevant to the check?
- Is the date realistic, and how would more time be asked for?
- Who will speak to HMRC during the check?
GOV.UK has HMRC's guide to getting help and support during a compliance check, including extra support if you need it and how to let a tax agent or someone else deal with HMRC for you, and says you can also get help and support using HMRC's online tool. GOV.UK: HMRC compliance checks, help and support [7]
You can authorise a friend, relative or voluntary organisation to talk to HMRC for you and help you fill in forms. You can also authorise an agent, such as an accountant or tax adviser, to deal with HMRC for you. [8]
Need help with this?
Vision Consulting Chartered Accountants and Registered Auditors, Tax Letters' founding partner, is regulated by ICAEW. Talk to them in confidence, with no obligation. [9] [10] [11]
Call 020 8554 2135How Vision handles HMRC compliance checks
You can also deal with HMRC directly, free, without any adviser. Free help: TaxAid, which says it helps “people who can’t afford to pay for help”, and Citizens Advice.
The two are connected. Tax Letters takes no referral fees.How Tax Letters is funded.
Keep a record
Keep this with the letter. A note of every request, date and reply helps later. Mark what happened:
Sources
Each source is linked, with the date Tax Letters last checked it.
- GOV.UK: About compliance checks, CC/FS1a (checked 7 Oct 2026)
- legislation.gov.uk: Taxes Management Act 1970, section 9A (checked 7 Oct 2026)
- GOV.UK: Use alternative dispute resolution to settle a tax dispute (checked 8 Oct 2026)
- legislation.gov.uk: Taxes Management Act 1970, section 28A (checked 8 Oct 2026)
- GOV.UK: Get help from HMRC if you need extra support (checked 7 Oct 2026)
- GOV.UK: Get help from HMRC if you need extra support, if you need more time (checked 7 Oct 2026)
- GOV.UK: HMRC compliance checks: help and support (checked 8 Oct 2026)
- GOV.UK: Appoint someone to deal with HMRC on your behalf (checked 7 Oct 2026)
- Vision Consulting: Contact us (checked 7 Oct 2026)
- TaxAid: About us (checked 8 Oct 2026)
- Citizens Advice: About us (checked 7 Oct 2026)