Check Your PAYE Tax Code: Has HMRC Removed Your Expenses and Gift Aid Relief?

What HMRC Changed?

HMRC uses your tax code to tell your employer how much income tax to deduct from your pay each month. That code includes allowances for things like employment expenses and Gift Aid relief on charitable donations. The problem in 2026 is that HMRC has started automatically removing these allowances from PAYE codes when it suspects your circumstances have changed even when they have not.

Two specific items are getting stripped:

• Employment expenses above £120 professional subscriptions, work-from-home costs, uniform maintenance, and similar flat-rate or itemised claims
• Higher-rate Gift Aid relief the additional relief that 40% and 45% taxpayers can claim on charitable donations

Why is HMRC making this assumption? The department pulls data feeds from employers, P800 reconciliations, and coding notices to detect changes in employment status, income levels, or benefit-in-kind adjustments. When the algorithm flags something even a change in employer or a pay rise it can trigger a code revision that wipes previous allowances.

The result is a smaller personal allowance in your tax code, which means higher monthly tax deductions. For someone with £600 in annual expenses coded in, losing that adjustment can cost £120 to £240 a year in extra tax, depending on their tax band. That comes straight off the monthly payslip without any warning letter arriving first.

This is why so many workers are asking: “Why did my tax code change?”

Who Is Likely Affected

This is not a niche problem. A wide range of employees can see their tax code adjusted:

• Employees who claim employment expenses teachers, engineers, healthcare workers, remote workers, and anyone using flat-rate expense claims
• Higher-rate taxpayers who donate to charity with Gift Aid declarations
• People who recently changed jobs or moved between PAYE schemes
• Retirees drawing pension income where HMRC is reconciling a new employer record alongside pension payments
• Anyone recently moved back onto PAYE after a period of self-assessment or contracting
• Late self-assessment filers whose 2024/25 returns have only recently fed back into HMRC’s coding system

It is also worth noting: if HMRC has incomplete information about your income or status, it may apply an emergency tax code instead of your normal one. An emergency tax code UK typically marked as 1257L W1 or M1 means your employer taxes each pay period in isolation, without using the cumulative allowances you are entitled to. This can cost significantly more tax in the short term and needs correcting as soon as possible.

What to Check on Your Payslip and Tax Code

Before calling HMRC, spend five minutes looking at your payslip and recent coding notice.

On your payslip, check:

• The tax code shown (usually a number followed by a letter, like 1257L or 900L)
• The year-to-date tax paid column has it jumped recently?
• Any week 1 / month 1 marker (written as W1 or M1 after the code), which signals a non-cumulative emergency basis

On your coding notice (form P2), check:

• The personal allowance figure it should normally be £12,570 for 2025/26
• Any deductions listed for expenses or Gift Aid have these been removed or reduced compared to last year?
• The date the notice was issued a notice issued in early 2026 with no prior contact from you is a red flag

A standard code of 1257L means a tax-free personal allowance of £12,570. If your code has dropped to, say, 900L, HMRC is assuming you have £3,570 less allowance available meaning you are paying tax on that extra amount each year.

Quick 3-Step Checklist Verify Your Tax Code Now

This checklist is designed to take under 20 minutes. Do it today if your pay has dropped unexpectedly.

Step 1: Log into your Personal Tax Account Go to gov.uk/personal-tax-account and sign in with your Government Gateway credentials. Under the “Pay As You Earn” section, you will see your current tax code and any recent coding notices. Check whether employment expenses or Gift Aid relief appear in the breakdown and compare what is there now against what was there last year.

Step 2: Match your payslip to the coding notice Take your most recent payslip and find the tax code. Compare it to the code shown in your Personal Tax Account. If the numbers do not match, or if an allowance that was there last year is now missing, note the exact amount and the date it was removed. That information is what you will need in the next step.

Step 3: Contact HMRC or your payroll team promptly Call HMRC’s income tax line (0300 200 3300) or use the webchat through your Personal Tax Account. Have your National Insurance number ready. If the error has affected several pay periods, ask explicitly about backdating the correction and getting a refund either through an adjusted tax code or directly via BACS.

For faster resolution, you can also ask your employer’s payroll department to apply a corrected coding notice as soon as HMRC issues it. This means the fix hits your next payslip rather than waiting for a tax year-end adjustment.

What to Say to HMRC or Payroll

Keep it short and factual. Something like this works:

“My National Insurance number is [XXXX]. I believe my PAYE tax code has been incorrectly updated in 2026. Employment expenses of [£X] and/or higher-rate Gift Aid relief have been removed without any change in my circumstances. I want to request reinstatement of these allowances, a revised coding notice, and confirmation of whether a backdated correction or repayment will apply.”

If HMRC Does Not Act Your Next Steps

Most corrections happen within two to three weeks of contacting HMRC. But if the issue is disputed or involves larger sums, here is what to do next:

• Submit a PAYE coding enquiry in writing this creates a formal paper trail
• Gather evidence receipts for work expenses, Gift Aid declarations from your charities, employer expense approval records
• Claim via self-assessment if you are already in self-assessment, include the disputed relief in your return; HMRC must process it
• Request a P800 review if you believe you have overpaid tax for the full year, HMRC may issue a P800 tax calculation after year end
• Speak to a tax adviser for amounts over £500 or if HMRC is unresponsive, a qualified tax adviser (look for members of the Chartered Institute of Taxation or ICAEW) can escalate on your behalf

Refunds for the current tax year normally process within four to six weeks once a corrected code is in place. For prior years, claims can generally go back four tax years.

How to Stop This Happening Again

The honest answer is that HMRC’s automated coding system is not always reliable when circumstances change. Here are a few things that reduce the risk:

• Keep your Personal Tax Account updated, especially if you change jobs or your income changes significantly
• File self-assessment returns on time late filing delays how expenses and Gift Aid relief feed back into your PAYE code
• Renew Gift Aid declarations with your charities regularly if a charity notifies HMRC that your donation has stopped, the related relief may be removed
• Tell your employer’s payroll team if you expect a coding notice to change, so they can apply it promptly
• Check your tax code at the start of each new tax year (April) rather than waiting to see an unexplained drop in pay

Has your take-home pay dropped this year without explanation? Check your Personal Tax Account today at gov.uk/personal-tax-account the process takes under 20 minutes and could put hundreds of pounds back in your pocket. If you are unsure what your tax code means or whether your allowances are correct, a free initial conversation with a tax adviser can save you time and money.