Getting a letter from HM Revenue & Customs can surprise you but it is in fact very common. HMRC sends a lot of letters every year to individuals or contractors around the UK for multiple reasons. The key is you should know how to react calmly and correctly on time.
It is never the right thing to not pay attention to any letter from HMRC. A simple looking letter can have hidden deadlines or legal obligations. If you miss to notice them you will have to pay penalties or HMRC will hold an investigation into your tax affairs.
This guide will explain everything about the different types of HMRC letters along with explaining each type. Also this article shares correct steps you should take to protect your position and stay compliant.
Don’t Ignore It – Why Every HMRC Letter Matters
It is very important that you should never ignore any letter from HMRC. The letter can be a regular notice or a request for some information. If you fail to respond within the deadline, you might be charged a penalty along with the interest. In some serious cases it might involve a formal investigation.
HMRC sends letters to individuals and businesses for multiple reasons. Some letters provide information about a change to your tax code or an update to your National Insurance record. Others need action on your part such as document submission or replying to a compliance enquiry. Whatever be the reason, the letter will always have a deadline that you must look into immediately.
“You must not ignore an HMRC letter. Failure to respond can result in penalties, interest, and formal enforcement action.” – GOV.UK
Step One: Check That the Letter Is Genuine
Before taking any action, verify that the letter is authentic. Fraudsters frequently impersonate HMRC in so-called ‘phishing’ scams, sending fake letters, emails, and text messages designed to steal personal and financial information.
HMRC maintains a published list on GOV.UK of genuine letters it sends, including specific reference codes. To check whether your letter is real:
- Visit GOV.UK and search ‘Check if a letter from HMRC is genuine’
- Look up your letter’s reference code against the official list
- Check that any QR codes in the letter lead to a GOV.UK page
- Verify the sender’s contact address ends in ‘hmrc.gov.uk’ for email correspondence
- Do not call any phone number printed on the letter unless you have confirmed it on GOV.UK
If you suspect a letter is fraudulent, report it immediately by emailing phishing@hmrc.gov.uk. Do not send personal details, bank information, or payments in response to a letter you cannot verify.
Common Types of HMRC Letters and What They Mean
Understanding the type of letter you have received is key to knowing what action to take. Here are the most common categories:
Tax Code Change Notification
HMRC issues letters when your tax code changes. Your tax code determines how much Income Tax is deducted from your pay each period. A change might result from a new job, a benefit in kind, underpaid tax from a previous year, or a change in your personal circumstances. Check the new code against your payslip to ensure it is being applied correctly.
Simple Assessment Letter (P800 or PA302)
A Simple Assessment letter calculates whether you owe tax or are due a refund at the end of the tax year, without requiring you to complete a Self Assessment tax return. Check the figures against your P60, bank statements, and any benefits letters. If the amounts are correct, you can pay any balance due or claim a refund. If you believe the figures are wrong, you have 60 days to contact HMRC and correct them.
Notice to File a Self Assessment Tax Return (SA316)
This letter confirms that HMRC expects you to complete a Self Assessment tax return for the relevant tax year. The deadline for filing online is 31 January following the end of the tax year. Missing this deadline triggers an automatic £100 penalty, with further daily penalties of £10 per day after three months.
Letter IDMS99 – Amount Overdue
This letter from HMRC’s Debt Management team informs you that a payment is overdue on your account. The letter specifies how to pay and warns that if you do not pay or contact HMRC within 28 days, further action may be taken. You must not ignore this letter. If you cannot pay in full, contact HMRC to discuss a Time to Pay arrangement.
Compliance Check or Enquiry Letter
This is one of the more serious letters you can receive. HMRC may open a compliance check (also called a tax enquiry) into your Self Assessment return, PAYE record, VAT returns, or business accounts. For Self Assessment returns filed on time, HMRC must open an enquiry within 12 months of the filing deadline. However, if errors are suspected, HMRC can go back four years for careless errors and six years for deliberate ones.
National Insurance Letter (CA4361 or CA2490)
HMRC may write to inform you of potential overpayments of National Insurance contributions, or to notify you of possible gaps in your Home Responsibilities Protection record (relevant to your State Pension). These letters typically ask you to provide information or complete an attached form.
VAT Registration Letter (VPCF1)
If HMRC has concerns about your VAT registration, you may receive a letter advising of their intention to cancel it. You have 30 days to provide evidence that you are legitimately registered for VAT. If you do not respond within 30 days, HMRC will proceed with deregistration.
Nudge Letter
A nudge letter is an informal prompt from HMRC suggesting that your tax affairs may need reviewing. For example, if HMRC’s data matching systems have identified undeclared income from online sales, rental income, or investments. Whilst nudge letters are not formal enquiries, you should take them seriously and seek professional advice promptly.
Step Two: Understand the Deadline and Gather Your Documents
Every HMRC letter requiring action will state a response deadline. Note this date immediately. If the letter is about a tax enquiry or compliance check, the letter will name the HMRC officer dealing with your case and include their direct contact details.
Depending on the type of letter, you may need to gather the following:
- P60 or P45 from your employer for the relevant tax year
- Self Assessment tax returns and SA302 calculations
- Bank statements showing income and expenditure
- VAT returns and invoices (for business queries)
- Payslips or pension statements
- Evidence of any allowable expenses or deductions you have claimed
- Correspondence with any previous accountant or tax adviser
Organising your records before responding helps ensure your reply is accurate, proportionate, and properly evidenced, all of which can limit your exposure to penalties.
Step Three: Respond Promptly and Accurately
Once you understand what HMRC is asking and have gathered your supporting documents, respond within the deadline stated in the letter. If you need more time, you can contact HMRC’s officer or helpline to request an extension. HMRC may grant additional time where there is a valid reason, such as serious illness or bereavement.
Failure to comply with a formal information notice can lead to an initial penalty of £300, plus daily penalties of up to £60 for continued non-compliance. Responding promptly and cooperatively demonstrates good faith and can materially reduce any penalties charged.
What If You Disagree With HMRC?
You have the right to challenge HMRC’s decisions. If HMRC amends your tax return or issues an assessment you believe is incorrect, you can:
- Request an internal review by HMRC’s Review Officer, who will independently assess the decision
- Appeal to the First-tier Tribunal (Tax), an independent body that hears tax disputes
- For Simple Assessment disputes, contact HMRC within 60 days of the letter date
- For penalty notices, you have 30 days from the date of the penalty notice to lodge an appeal
Always seek professional advice before appealing. An experienced accountant or tax adviser can assess the strength of your position, prepare the most effective response, and represent you throughout the process.
What If You Cannot Pay What HMRC Says You Owe?
If you receive a letter confirming a tax debt you cannot pay in full, do not ignore it. Contact HMRC as soon as possible to discuss a Time to Pay (TTP) arrangement. HMRC will often agree to a structured repayment plan where you pay the debt in monthly instalments. Interest will continue to accrue on the outstanding balance, but setting up a TTP prevents further enforcement action.
You can apply for a Time to Pay arrangement online for Self Assessment debts of up to £30,000 if you have filed your return and the debt is within 60 days of the payment deadline. For larger debts or more complex situations, you will need to call HMRC’s Payment Support Service.
How Lexarox Accounts Can Help?
At Lexarox Accounts, we are fully registered as HMRC Authorised Agents, and our team of qualified accountants regularly handles HMRC correspondence on behalf of individuals, sole traders, limited companies, and contractors across the UK.
If you have received a letter from HMRC, we can:
- Review the letter and explain clearly what it means for you
- Act as your authorised agent and communicate directly with HMRC on your behalf
- Prepare accurate and proportionate responses to compliance checks and enquiries
- Advise on penalty mitigation and voluntary disclosure where appropriate
- Represent you through the appeals process if you disagree with HMRC’s decision
- Help you set up a Time to Pay arrangement if you cannot meet a tax debt immediately
- Ensure your records and filings are fully compliant to prevent future issues
Do not face HMRC alone. Contact Lexarox Accounts today on 0208 533 1358 or email info@lexaroxaccounts.co.uk for prompt, professional support.
Frequently Asked Questions (FAQs)
What should I do first when I receive a letter from HMRC?
Read it carefully, note the deadline, check it is genuine on GOV.UK, and seek professional advice if unsure.
How do I know if my HMRC letter is a scam?
Check the letter reference against GOV.UK’s list of genuine HMRC letters. Report suspected scams to phishing@hmrc.gov.uk.
What happens if I ignore a letter from HMRC?
Ignoring HMRC correspondence leads to escalating penalties, interest, and potential formal enforcement or investigation action.
How long do I have to respond to an HMRC compliance check letter?
HMRC normally specifies a deadline in the letter. Typically, you have 30 days, though extensions may be granted.
Can HMRC investigate past tax years?
Yes. HMRC can review up to four years for careless errors, and six years for deliberate inaccuracies under current rules.
What is a Simple Assessment letter and do I need to do anything?
It calculates your tax position without Self Assessment. Check the figures; pay any balance, or dispute within 60 days.
What is a nudge letter from HMRC?
An informal prompt suggesting possible undeclared income. Not a formal enquiry, but should be reviewed with a professional promptly.
