Despite repeated statements about reducing paper correspondence, HMRC is preparing to send around 1.4 million letters to taxpayers who owe income tax outside the PAYE and self assessment systems.
Known as ‘simple assessments’, these letters are not new but are being sent in larger numbers this year. The purpose is to prompt individuals to settle unpaid tax, especially where HMRC believes the person may be unaware that they owe anything. These assessments commonly apply to pensioners, people with second incomes, or those earning through platforms like Airbnb, Etsy, or eBay.
Each letter will contain a personalised summary of the unpaid tax, typically relating to income earned above the personal allowance threshold. It will also set out the amount due and how to pay it. The deadline for payment is 31 January 2026, giving people ample time to prepare. However, HMRC encourages recipients to review their records and check the figures provided.
Who will receive a simple assessment?
There are several reasons someone might receive one of these letters. It could be due to:
- Untaxed interest from savings or dividends
- Receiving personal allowances not due
- Earning untaxed income from property rentals or side jobs
- Tax owed on pension income
HMRC stresses that taxpayers should not ignore the letter. If the assessment contains a mistake, it must be queried within 60 days of receiving the notice. Queries should be raised via the official government website. If HMRC agrees with the proposed correction, a revised calculation will be issued in a second letter.
If HMRC disagrees with the challenge, the taxpayer still has the right to appeal, but only within 30 days of that second decision. Failing to act within these timeframes could lead to missed opportunities to correct errors or challenge unfair assessments.
While these simple assessments continue to be sent by post, they sit awkwardly alongside HMRC’s broader push to digitise taxpayer communication. Earlier this year, the tax authority publicly reaffirmed its plans to move towards online-first services and reduce reliance on physical mail. It estimates that switching to digital could save the government £50m by 2028/29.
One part of this digital shift involves the HMRC app. Taxpayers registered on the app may receive email or SMS notifications alerting them to new messages or updates in their online account. However, only those using the app will receive digital contact. It has been clear that HMRC will not send messages this way to those who haven’t registered.
As part of its cost-saving plan, HMRC stopped sending six types of corporation tax letters in July 2025, labelling them ‘non-essential’. These included reminders and duplicate notifications that could be accessed through online accounts.
Digital first agenda
However, simple assessment letters remain a notable exception to HMRC’s digital-first agenda. With such large volumes still going out by post, it’s clear that paper communications remain a key tool for reaching taxpayers who may not realise they owe tax or are less likely to engage online.
Taxpayers receiving one of these letters are advised to act quickly, seek professional advice if needed, and avoid delaying their response, particularly if they believe there has been an error.
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