Receiving a letter from HM Revenue & Customs (HMRC) can be unsettling, especially when it concerns tax matters. Whether it’s a simple query, a request for clarification, or a notice of investigation, knowing how to respond calmly and correctly can prevent unnecessary stress or penalties. At CMA Accountancy, we guide clients through every stage of communication with HMRC, ensuring their affairs are compliant, accurate, and professionally handled.

Understanding the Type of HMRC Letter You’ve Received

Not all HMRC letters indicate wrongdoing. Many are routine, requesting additional information or confirming recent submissions. The key is to identify the letter’s purpose early.

Common types include:

• Tax calculation notices (P800 or Simple Assessment): These indicate HMRC believes you have overpaid or underpaid tax.
• Information requests: HMRC may seek clarification on figures from your self-assessment return or business accounts.
• Compliance checks: These are audits to confirm that your tax affairs are correct and up to date.
• Payment demands or penalty notices: These indicate overdue amounts or late filing penalties.

Understanding the nature of the letter determines your next step — and how urgently you need to act.

Step One: Do Not Ignore the Letter

HMRC correspondence always includes a response deadline. Failing to respond on time can escalate the issue, potentially leading to additional fines or legal enforcement. Even if you suspect an error, you must acknowledge the letter.

At this stage, do not destroy, discard, or attempt to alter any documents. Keep the letter and all relevant paperwork in one place — including tax returns, receipts, and communication logs.

Step Two: Check for Legitimacy

HMRC scams have become increasingly sophisticated. Genuine letters will contain your correct name, address, and a unique reference number (usually starting with letters such as COTAX, UTR, or PAYE).

You can verify legitimacy by:

• Checking the return address against HMRC’s official contact details.
• Calling HMRC directly using the numbers on the government’s official website — not those printed on the letter if you suspect fraud.
• Consulting your accountant before replying or providing any personal information.

CMA Accountancy frequently assists clients in identifying whether correspondence is authentic and determining the best response approach.

Step Three: Review the Content Carefully

Once authenticity is confirmed, read the letter in full. Take note of:

• What HMRC is asking for (specific documents, explanations, or figures).
• Which tax years are affected.
• Any deadlines or potential penalties.

If the issue relates to self-assessment, corporation tax, or PAYE, ensure you cross-check your submitted records for accuracy. Many HMRC letters arise from mismatched data between systems, employers, or banks.

Step Four: Seek Professional Advice

HMRC’s tax code is complex, and even a minor misunderstanding can lead to unnecessary costs. Professional advice from an accountant such as CMA Accountancy ensures your response is compliant, evidence-based, and strategic.

An accountant can:

• Review and verify the figures in question.
• Draft your written response to HMRC.
• Liaise directly with HMRC on your behalf.
• Identify any tax reliefs or corrections that can mitigate liability.

CMA Accountancy specialises in handling HMRC enquiries swiftly, helping clients resolve disputes while maintaining full compliance.

Step Five: Prepare Your Response

If you are responding directly to HMRC, always include:

• The reference number from the letter.
• Copies (not originals) of supporting documents.
• A concise, factual explanation addressing each query.

Maintain a polite and professional tone. Never speculate — only state verifiable information. Sending inaccurate or incomplete responses can prolong the enquiry or trigger further review.

Step Six: Keep Records and Follow Up

Keep copies of all correspondence and any proof of postage or email confirmation. If you’ve not received a reply within a few weeks, follow up to confirm receipt.

HMRC may take time to process responses, particularly during peak periods. However, maintaining a clear record of communication demonstrates due diligence, which can be valuable if a dispute arises later.

Step Seven: If You Owe Tax, Act Promptly

If the letter confirms an underpayment, arrange payment as soon as possible to avoid further interest or penalties. In cases of financial hardship, HMRC may allow a Time to Pay arrangement, enabling you to spread the amount owed across several months.

CMA Accountancy can negotiate such arrangements on your behalf, ensuring affordability and compliance.

When to Escalate Matters

If you believe HMRC’s findings are incorrect, you are entitled to request a review or appeal the decision. Appeals must be made within strict time limits — typically 30 days from the date of the notice.

Having professional representation during this stage greatly improves your chances of success, as an experienced accountant can present a factual, well-documented case that aligns with HMRC’s procedural standards.

Conclusion

A letter from HMRC doesn’t always mean you are in trouble — but it does mean you must take the matter seriously. Acting promptly, maintaining organised records, and seeking professional advice can prevent complications and often lead to a quick resolution.

At CMA Accountancy, we assist individuals and businesses across the UK with all aspects of tax compliance and HMRC correspondence. From first contact to final resolution, our expertise ensures you remain protected, informed, and in full control of your tax affairs.