HMRC Sending Assessment Letters to UK Taxpayers and Pensioners – What You Need to Know

HMRC is sending Simple Assessment letters to around 560,000 UK taxpayers this year, including approximately 140,000 pensioners. These official tax calculation notices inform recipients of Income Tax owed on income that cannot be collected through PAYE, such as untaxed State Pension payments exceeding the personal allowance. Recipients should verify the letter’s authenticity, understand the payment deadline, and know their options for disputing or arranging payment if the amount appears incorrect.

The letters, issued for tax years including 2023/24, are genuine notifications based on data gathered from employers, pension providers, banks, and the Department for Work and Pensions. They do not require a Self Assessment return unless the recipient chooses to dispute the figures. Understanding what these letters contain, who receives them, and how to respond can help affected taxpayers navigate the process without unnecessary worry.

What is HMRC Simple Assessment?

Simple Assessment is HMRC’s method of calculating Income Tax for individuals whose income falls outside the PAYE system and who do not file a Self Assessment return. When tax cannot be collected automatically, HMRC issues a letter setting out exactly what is owed and why.

Key Insights About These Letters

• Letters are issued for income that cannot be taxed through PAYE, such as untaxed State Pension above the personal allowance
• HMRC calculates tax using data from employers, pension providers, banks, and DWP
• Pensioners receiving State Pension as their primary income are particularly affected
• No Self Assessment return is required unless the recipient disputes the calculation
• Multiple letters may be issued for different tax years or income sources
• Scammers frequently mimic these letters—verifying authenticity is essential

Snapshot of Key Facts

Why Have I Received a Simple Assessment Tax Calculation Letter?

These letters arrive when HMRC determines that Income Tax is owed on income that was not taxed at source. Unlike PAYE where tax is automatically deducted from wages or occupational pensions, certain income streams require a separate calculation.

Pensioners and State Pension Income

Pensioners frequently receive Simple Assessment letters because the State Pension is taxable but not always covered by a PAYE tax code. When the State Pension is the only income above the £12,570 personal allowance, any amount over that threshold becomes liable for Income Tax. The tax is calculated based on the total income figure, taking into account any reliefs the recipient may be entitled to claim.

State Pension is paid in 4-weekly instalments rather than monthly. When verifying the figures in the letter, recipients should multiply their regular payment by 13 to calculate the annual amount. This matches the method HMRC uses and avoids confusion caused by the timing of deposits in bank accounts.

What the Letter Shows

Page 2 of the Simple Assessment letter contains a detailed breakdown of the calculation. This includes all income sources considered, such as PAYE earnings (which can be cross-checked against P60 or P45 documents), State Pension entitlement, dividends, and benefits. It also lists any deductions applied, including reliefs like Marriage Allowance, pension contributions, and Gift Aid donations.

Recipients can verify the figures independently using HMRC’s online tax checker or their Personal Tax Account. If anything appears unclear, contacting HMRC directly or seeking advice from a qualified tax advisor is recommended before the payment deadline passes.

Is My HMRC Simple Assessment Letter Fake?

All Simple Assessment letters described in official HMRC guidance are genuine communications. However, scammers frequently send convincing fakes designed to steal money or personal information. Knowing how to distinguish authentic letters from fraudulent ones is crucial.

Signs of a Genuine Letter

Authentic Simple Assessment letters come from HMRC and include a unique taxpayer reference (UTR) or PAYE reference number matching the recipient’s records. The letter explains the tax calculation in detail and provides payment instructions through official channels. For overdue reminders marked IDMS99P, the letter directs recipients to call the official HMRC number 0300 322 7835.

Red Flags Indicating Fraud

Suspicious indicators include unsolicited emails—HMRC never sends notifications via email from addresses outside @hmrc.gov.uk. Fake letters often demand immediate payment through gift cards, cryptocurrency, or unusual bank transfers. Requests to provide personal details through links in emails or messages are hallmarks of scams.

How Do I Contact HMRC About Simple Assessment?

If the calculation appears incorrect or you need to discuss your Simple Assessment, HMRC provides several contact methods. The appropriate route depends on whether you are querying the calculation, reporting an error, or arranging payment.

Disputing an Incorrect Calculation

Recipients who believe their Simple Assessment contains errors have 60 days from the date of the letter to contact HMRC. Errors should be specified in writing, with the correct figures clearly identified. Supporting documentation such as P60 forms, bank statements, or DWP notification letters should be included where possible.

HMRC will review the information provided and either issue a revised letter if the error is agreed upon, or respond with an explanation. If the disagreement remains unresolved, the recipient may have grounds for a formal appeal. Importantly, payment should still be made by the original deadline unless HMRC explicitly agrees to extend it.

Online Contact Options

The GOV.UK Simple Assessment page provides access to guidance and, for recent tax years, the ability to view calculations online. The Personal Tax Account system allows taxpayers to check their tax position, verify income details, and message HMRC securely. For complex disputes or telephone enquiries, calling HMRC directly remains the quickest route to resolution.

What Are the Simple Assessment Payment Plan Options?

When a Simple Assessment shows tax owed, payment must reach HMRC by the deadline specified in the letter. Failing to pay on time can result in penalties and interest charges, making it important to either pay in full or establish a payment arrangement as early as possible.

Payment Deadlines for 2023/24

Paying Early or in Instalments

HMRC allows voluntary early payment and instalment arrangements without prior agreement, provided the full amount is settled by the deadline. For example, someone owing £1,200 could arrange to pay £200 per month over six months without needing a formal Time to Pay arrangement. Online payment through GOV.UK is available for tax years 2022/23 onwards.

For those unable to pay the full amount by the deadline, formal payment plans may be available through the Time to Pay scheme. These are typically considered for larger debts or where genuine financial hardship exists. The official Simple Assessment guidance provides further details on eligibility and the application process.

Timeline: What to Expect After Receiving Your Letter

Understanding the sequence of events following a Simple Assessment can help recipients plan their response effectively. The process follows a predictable pattern from issuance through to resolution.

1. 5 April – End of the tax year. HMRC begins processing data gathered throughout the year from employers, banks, and DWP.
2. May-June – HMRC calculates Simple Assessments for taxpayers with untaxed income exceeding their allowances.
3. July-August – Letters are sent to approximately 560,000 recipients, including around 140,000 pensioners.
4. Within 60 days – Recipients who believe their calculation is incorrect must contact HMRC to dispute.
5. 31 January 2025 – Primary payment deadline for 2023/24 tax year letters received before 31 October 2024.
6. Ongoing – Additional letters may arrive for different income sources or tax years, requiring separate responses.

Genuine Letters vs. Scams: What Is Clear and What Remains Uncertain

The Simple Assessment process is well-documented through official channels, but recipients still encounter confusion around authenticity and next steps. Below is a comparison of established facts versus areas where uncertainty commonly arises.

The Context Behind These HMRC Communications

Simple Assessment letters represent HMRC’s approach to taxing income that falls outside the PAYE system. The initiative gained prominence as more pensioners began receiving State Pension with tax codes that did not fully account for their total income position.

The State Pension tax implications affect many retirees who may have other income sources such as private pensions, savings interest, or part-time work. When combined, these can push total income above the personal allowance while remaining untaxed at source.

The scale of the current mailing—affecting around one in four pensioners receiving these letters—reflects both the growing number of pensioners and the increased complexity of retirement income streams. HMRC’s move toward data-driven assessment rather than requiring self-assessment returns simplifies the process for many, though it places the burden of verification on recipients.

Sources and Official Guidance

The information in this article draws on official HMRC publications and guidance from recognized tax advisory organizations. Primary sources include the GOV.UK Simple Assessment pages and the Low Incomes Tax Reform Group, which provides free guidance specifically designed for those with limited tax knowledge.

“HMRC uses information from employers, pension providers, banks and the Department for Work and Pensions to calculate the tax due. Recipients do not need to file a Self Assessment return unless they wish to dispute the calculation.”

— GOV.UK Simple Assessment Guide

“Simple Assessment letters have been sent to around 560,000 people, including approximately 140,000 pensioners who may be receiving them for the first time.”

— Low Incomes Tax Reform Group, August 2024

Summary: Key Takeaways

HMRC Simple Assessment letters are genuine tax notifications sent to individuals who owe Income Tax on income not covered by PAYE. Recipients should verify the letter’s authenticity using official GOV.UK tools, check the figures against their own records, and either pay the amount due or contact HMRC within 60 days if disputing the calculation. Payment deadlines depend on when the letter was received, with 31 January 2025 being the key date for most 2023/24 tax year assessments.