# Received a letter from HMRC? What to gather before asking for tax help

> What an HMRC tax compliance letter means, a checklist of documents to gather, and how to prepare a clear response to an HMRC enquiry.

Canonical: https://yestax.co.uk/tax-help/hmrc-letter-what-to-gather
Last updated: 2026-09-10
Published: 2026-09-03
Author: YesTax Editorial Team
Reviewed by: Qualified Tax Investigation Specialist (CTA)

> **Key Takeaways: Received an HMRC Letter?**
> - **What it is:** A tax compliance letter means HMRC has opened an enquiry into your Self Assessment, VAT, or Corporation Tax return—ranging from a simple verification check to a detailed audit.
> - **Strict Deadlines (Typically 30 Days):** Always note the response deadline at the top of the letter. Missing it can trigger automated daily penalties.
> - **Keep Full Documentation:** Do not reply piecemeal. Gather all corresponding invoices, contracts, bank statements, and past returns before submitting your response.

If HMRC has contacted you about a compliance check or tax enquiry, **start by preserving the letter and identifying exactly what HMRC is asking for and by when**. Good advice becomes much easier when the adviser can see the actual correspondence rather than a remembered summary of it.

## What is a tax compliance letter?

A **tax compliance check letter** is HMRC’s formal way of asking for evidence to verify that your tax declarations are accurate. HMRC regularly matches third-party data (from banks, letting platforms, crypto exchanges, and overseas tax authorities) against submitted returns. When discrepancies or random audit selections occur, a compliance check letter is issued.

## The first things to capture

Before doing anything elaborate, write down or scan these basics:

- the date on HMRC's letter or message;
- any date by which HMRC asks you to reply;
- the tax, tax return or tax years mentioned;
- any amount of tax, interest or penalty shown;
- the HMRC office, caseworker or reference shown on the correspondence;
- exactly what information or documents HMRC has requested.

HMRC says a compliance check can involve checking an individual's or a business's tax position and may include requests for information or documents. The scope can vary substantially, which is why the original correspondence matters.

## Keep the whole chain of correspondence

Do not keep only the latest letter. Put the relevant communications together in date order.

That can include:

1. HMRC letters and notices;
2. messages sent through an HMRC online account;
3. replies already sent to HMRC;
4. notes of telephone conversations;
5. letters or emails sent by a previous accountant or adviser.

A timeline often reveals the issue faster than a pile of disconnected documents.

## Gather the records behind the issue

The useful records depend on what HMRC is checking. Examples may include:

| If HMRC is asking about | Records that may be useful |
| --- | --- |
| Business income or expenses | Accounts, invoices, receipts, bank records and bookkeeping exports |
| Property income | Rental statements, agent records, expense invoices and ownership information |
| Employment | P60s, P45s, payslips and benefits information |
| Investments or disposals | Purchase records, sale records, broker statements and transaction histories |
| Overseas matters | Foreign tax documents, income statements, residence information and relevant dates |

Do not manufacture missing records or guess at figures simply to make a file look complete. Identify what exists, what is missing and what may need reconstructing.

## Separate facts from assumptions

It is useful to distinguish between:

- **what HMRC says** in the correspondence;
- **what actually happened** according to you and your records;
- **what you are unsure about**.

That is more useful than deciding in advance that HMRC is definitely right or definitely wrong.

## What to tell YesTax

You do not need to upload a complete tax file simply to start an enquiry. A concise description plus the two most relevant follow-up answers is enough for initial triage.

Useful details often include the response date, tax years involved, approximate amount at issue and a short explanation of why you think HMRC has contacted you.

> Do not send passwords, payment-card details or account login credentials through an enquiry form.

## The point of preparing this information

The objective is not paperwork for its own sake. It is to let someone reviewing the problem answer three basic questions quickly: **what has HMRC opened, what does HMRC want next, and what facts or records could change the answer?**

## Common questions

### What is a tax compliance letter from HMRC?

An HMRC tax compliance letter (often titled 'Compliance Check' or 'Check of your tax return') is an official notice that HMRC is reviewing specific figures, declarations, or full accounts for a tax year.

### Should I ignore an HMRC compliance-check letter if I think it is wrong?

Never ignore it. Failing to respond by the stated deadline can result in statutory penalties (under Schedule 36 FA 2008) and formal assessments based on HMRC's estimates.

### What information is most useful when asking an adviser for help with an HMRC letter?

The full letter with reference codes, the exact deadline, copies of the submitted tax returns, underlying bank statements, receipts, and any previous correspondence with HMRC.

## Primary sources
- [HMRC: Tax compliance checks](https://www.gov.uk/tax-compliance-checks)
- [HMRC compliance checks: help and support](https://www.gov.uk/guidance/hmrc-compliance-checks-help-and-support)

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This page is general information, not individual tax, legal or financial advice.