Have you overpaid tax? 7 money-saving checks for UK workers

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A pay rise is not the only reason to look again at your take-home pay. A job change, work costs you paid yourself or an allowance you never checked could all be worth a second look. That does not mean a refund is waiting for everyone. These seven checks will help you spot possible mistakes and missed relief, work out which records you need and decide what to do next.

1. Check your tax code against your payslip

Find the tax code on a recent payslip and compare it with the one shown in your HMRC online account or the HMRC app. Your code helps your employer work out how much Income Tax to take through PAYE, so an incorrect one can mean you pay too much or too little. Check that HMRC has the right details for your jobs and estimated income, particularly if your circumstances have changed.

Do not assume an unfamiliar code is wrong: different codes can reflect different circumstances. If the details do not match, update your information with HMRC and check subsequent payslips for a change. HMRC’s guidance on paying too much or too little taxexplains how it handles a correction once it has the income details it needs. Keep older payslips too, so you can see when a possible discrepancy began.

2. Review emergency tax after changing jobs

Your first payslip from a new employer deserves a closer look. If the employer does not have the information needed to work out your tax position, a temporary emergency tax code may be used. That can affect how much tax comes off your pay while the details are being sorted out, but seeing an emergency code does not, by itself, prove you are owed money.

Give your new employer the P45 from your previous job if you have it. If you do not, complete the starter checklist so the employer can pass on the relevant details. Then compare your next payslip with the first one and check whether HMRC has updated your record. If you had another job at the same time, mention that when checking your details rather than assuming the new employer has the full picture. Save both payslips: they make it easier to explain what changed.

3. Check uniform, workwear and tools

Did you pay to clean, repair or replace a uniform required for your job? Did you buy tools or protective clothing you needed to do the work? Some employees can claim tax relief on qualifying costs they paid themselves, provided their employer did not reimburse them. This can be easy to miss if each purchase or laundry cost felt too small to investigate at the time.

The distinction is between a qualifying work requirement and an everyday purchase. Ordinary clothes do not automatically count just because you wear them to work, and an optional upgrade to your kit is not necessarily an allowable expense. Check the rules for the specific item and your occupation before adding it to a claim. Some qualifying jobs have a flat-rate expense allowance, often £60 to £140 a year with no receipts needed; a claim based on actual costs may require receipts.

Keep a note of what you bought, why your job required it and what, if anything, your employer paid towards it. HMRC’s employee tax relief guidance is a useful place to check the basic conditions.

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4. Review business mileage, not your commute

If you use your own vehicle for work journeys, compare your records with the mileage payments you received from your employer. You may be able to claim Mileage Allowance Relief where qualifying business travel was not covered in full. HMRC's approved rate is 55p a mile for the first 10,000 business miles from 6 April 2026 (45p for earlier years) and 25p after that, and you can claim the gap between that and what your employer paid.

That does not make every trip to work claimable: the ordinary journey between home and a permanent workplace is generally commuting, not business mileage. Personal trips are excluded too.

Look back at journeys between work locations or to temporary assignments, and check the rules that apply to each trip rather than relying on a rough total from your calendar. Record the date, destination, reason for travel and miles driven. If your employer paid you for mileage, note how much; a claim needs to account for those payments. Reconstructing the journeys accurately is more useful than guessing a large figure that you cannot support.

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5. Check professional subscriptions and fees

Some jobs involve a subscription to a professional body or fees for an approved organisation. If you paid personally and your employer did not reimburse you, check whether the organisation and payment qualify for tax relief. Being related to your industry is not enough on its own: HMRC’s rules and its list of approved professional organisations matter.

Start with your bank statements, membership renewal emails or receipts, then match each payment to the tax year in which you made it. Ask your employer whether it already paid or refunded any of the cost, especially if your contract or benefits have changed. Do not claim a fully reimbursed fee again. If your membership is partly for personal interest rather than your work, check the applicable rules before treating the whole payment as a work expense.

6. See whether Marriage Allowance applies

Marriage Allowance is a household check, not an expense you put on a work claim. It may help if you are married or in a civil partnership, one partner has income below their Personal Allowance and the other meets the relevant tax-band conditions. The lower-income partner can transfer £1,260 of their unused Personal Allowance to the other partner, worth up to £252 a year, and a missed claim can be backdated up to four years.

You need to consider both incomes: transferring an allowance changes each person’s tax position, so it is worth checking whether the couple benefits overall.

If you think you missed it in an earlier tax year, check the conditions for that year and the current backdating window before making a claim. A change in either partner’s earnings could affect eligibility from one year to the next. Scottish income tax bands can also affect whether the receiving partner qualifies, so do not rely on a rule of thumb based only on where your employer is located. Have both partners’ income details to hand when you check.

7. Estimate a possible rebate and check the claim window

Once you have identified a possible issue, put the relevant payslips, P45s, receipts and mileage records together. A tax rebate calculator can help you estimate whether the last four tax years are worth checking more closely. An estimate is a starting point, however, not an HMRC decision or a promise that you will receive the amount shown.

For work expenses, the amount you spent is not the amount you get back. Tax relief depends on your eligible costs and the tax you paid. For example, £60 of qualifying expenses at a 20% tax rate could mean £12 of relief, not a £60 refund. If you paid too much tax because of a code error, that is a different calculation; compare the tax deducted with your actual position rather than adding up expenses alone.

Employment-expense claims generally need to be made within four years from the end of the tax year concerned. As of autumn 2026 that covers 2022/23 to 2025/26, and 2022/23 closes on 5 April 2027, so check the oldest year first. You can check and claim directly through HMRC, or choose a claims service if you would rather have help. Taxpro is one paid option: for PAYE refund claims its fee is 37.5% plus VAT, taken from the refund. Check the terms and the amount you would keep before deciding which route suits you.

The useful next step is a small bit of paperwork, not a guess at a refund. Compare your payslips with HMRC’s details, separate eligible work costs from ordinary spending and gather evidence for any year you want to check. If something still looks wrong, raise it while the relevant claim window is open. Even if the answer is that your tax was right, you will have a clearer picture of your pay and what to watch for next time your circumstances change.