Simple Assessment Explained: HMRC Tax Letters in 2026

Quick answer

A Simple Assessment is a tax calculation HMRC works out for you and sends in a letter, instead of asking you to complete a Self Assessment return. It uses data HMRC already holds -- such as your State Pension, employment income and bank interest -- to show the Income Tax you owe for a tax year. You check the figures against your own records, then pay the amount due by the deadline on the letter.

What a Simple Assessment is

Most people in the UK pay Income Tax automatically through PAYE, where tax is deducted from wages or a pension before the money reaches them. But PAYE cannot always collect the full amount. When there is a gap -- for example because the State Pension is paid gross, or savings interest exceeds your allowances -- HMRC needs another way to collect the tax. Historically that meant pushing people into Self Assessment, even when their affairs were simple. Simple Assessment exists to avoid that.

Under a Simple Assessment, HMRC does the calculation itself. It draws on figures reported by employers, pension providers, the Department for Work and Pensions and banks, works out your total taxable income, applies your allowances and the relevant tax bands, and tells you the result. You do not have to enter anything online. Your job is to check the maths, not produce it.

The letter is usually labelled as a Simple Assessment and may carry a form reference such as PA302. It will list each source of income HMRC has used, the allowances it has given you, the tax due, and how and when to pay.

Who receives one

HMRC generally uses Simple Assessment where your affairs are too simple to justify a full return but too tangled for PAYE to handle alone. Typical situations include:

• Pensioners whose combined State Pension and private pension income exceeds the Personal Allowance, leaving a small balance of tax to collect.
• Savers with taxable interest above their allowances that cannot be recovered through a tax code.
• People who underpaid tax in an earlier year that HMRC cannot fully claw back through future PAYE coding.

If your situation is more involved -- self-employment, substantial rental profits, high dividends or capital gains -- HMRC will normally keep you in Self Assessment instead, because those figures are not something it can reliably calculate without your input.

The 2026/27 figures that drive the calculation

A Simple Assessment is only as good as the rates behind it, so it helps to know the headline numbers for the 2026/27 tax year, which runs from 6 April 2026 to 5 April 2027. The table below covers the core Income Tax position for England, Wales and Northern Ireland.

The Personal Allowance is frozen at GBP 12,570 until April 2028, and it tapers away by GBP 1 for every GBP 2 of income above GBP 100,000, reaching zero at GBP 125,140. That taper creates an effective 60% tax band between GBP 100,000 and GBP 125,140, which matters if your income is near that level. Scotland sets its own Income Tax bands, so a Scottish taxpayer's assessment will use the Scottish rates rather than the figures above.

How to check your Simple Assessment

Do not assume the calculation is right just because it came from HMRC. The data feeding it can be incomplete, duplicated or out of date. Work through the letter methodically.

Step 1: confirm every income source

Compare each line on the assessment with your own paperwork: State Pension award letters, P60s and P45s from employment, private and workplace pension statements, and interest certificates from banks and building societies. A source that is missing, listed twice, or shows the wrong amount will change the tax due.

Step 2: check the allowances and bands

Confirm the Personal Allowance shown is GBP 12,570, unless your income is high enough for the taper to reduce it. Then check that the right tax bands have been applied -- 20% up to GBP 50,270 of taxable income, 40% above that. If you live in Scotland, the assessment should use the Scottish rates instead.

Step 3: recreate the total

It is worth rebuilding the calculation yourself. Add up your taxable income, subtract your Personal Allowance, and apply the bands to the remainder. Our

tool does this for you and is a quick way to see whether HMRC's bottom line looks plausible. If you also want to understand how tax is normally taken from earnings, the calculator shows the PAYE position, and the savings interest tax calculator helps where interest is part of the bill.

Step 4: keep records

Save the letter, your supporting documents and any workings. If you later need to query the figure, having everything in one place makes the conversation with HMRC far easier.

How and when to pay

The letter sets out how to pay and by when. You can typically pay through your HMRC online account, the gov.uk pay service, bank transfer or debit card. Always quote the reference printed on the assessment so the payment is matched to your record.

As a general rule, HMRC asks for payment by 31 January following the end of the tax year, or within three months of the date of the letter if that is later. Because the exact date depends on when your assessment was issued, rely on the deadline printed on your own letter rather than a generic figure -- and pay early if you can, to remove any risk of interest.

If you cannot pay in full, contact HMRC before the deadline. A Time to Pay arrangement, spreading the cost over instalments, may be available. The worst response is to do nothing: the tax remains due, and interest and possible penalties only add to the bill.

How to challenge a figure you think is wrong

If the calculation looks wrong, you can query it -- normally within 60 days of the date on the letter. Set out clearly what you believe is incorrect and attach evidence, such as a corrected interest certificate, a missing allowance, or proof that a source of income has been double-counted. HMRC will review the calculation and issue a revised assessment if it agrees with you.

While the query is being considered, keep paying any part of the bill you do not dispute, and keep copies of everything. If you remain unhappy after HMRC's review, there is a further appeals route you can ask HMRC to explain, but most genuine errors are resolved at the first stage once the right evidence is provided.

Simple Assessment versus Self Assessment

These two systems are easy to confuse, so it helps to be clear on the difference.

A Simple Assessment applies to a single tax year. Your circumstances can move you between the two systems over time -- starting a business might push you into Self Assessment, while a retiree winding down complex affairs might move the other way. Always check which system HMRC is using for each year, rather than assuming last year's position still applies.

Common pitfalls to avoid

• Assuming it is a scam. Genuine HMRC letters do exist, but so do fakes. Verify through your official gov.uk account rather than clicking links in unexpected emails or texts, and never share login details.
• Ignoring the deadline. The tax is legally due whether or not you respond. If you think it is wrong, query it -- do not simply set the letter aside.
• Forgetting savings interest. Banks report interest to HMRC automatically. If you have several accounts, the total can be higher than you remember, so check it against your statements.
• Overlooking the Scottish rates. Scottish taxpayers have different bands, so a quick mental check against English figures can mislead.

The bottom line

A Simple Assessment takes the admin of a tax return off your hands, but it does not remove your responsibility to check the figures. Read the letter carefully, match every line to your own records, confirm the GBP 12,570 Personal Allowance and the correct bands have been applied, and pay by the deadline using the reference shown. If something looks wrong, query it promptly with evidence. A few minutes spent verifying the calculation -- and running the totals through our

calculator -- is the best protection against paying more, or less, than you actually owe.