Am I due tax back? Quite possibly, if during any of the last four tax years you changed jobs, had a spell out of work, were put on an emergency tax code, or never claimed a relief you were entitled to. HMRC’s PAYE system estimates tax across the year and often takes too much when your circumstances shift. You have four years from the end of the tax year to claim it back, so overpayments going back to 2022/23 are still recoverable until 5 April 2027.
Why You Might Have Overpaid
PAYE spreads your £12,570 personal allowance across every payday and assumes your earnings will continue at roughly the same rate for the full twelve months. Whenever real life diverges from that assumption, the deduction is almost always too high rather than too low.
Emergency Tax Codes
Starting a new job without handing in a P45 often triggers an emergency code. You can spot one by the ending: W1, M1, or X (for example, 1257L M1). These codes treat each payslip in isolation, taxing you as though that single payment represents your earnings for the whole year. Usually it corrects itself once HMRC has your full employment history, but if it doesn’t, you need to chase the difference.
Job Changes and Gaps
Moving from a well-paid role to a lower-paying one is one of the most common causes of overpaid tax, because PAYE will have been deducting at a rate set for the old salary. Unemployment creates the same problem: your personal allowance keeps accruing while you’re not earning, so tax collected during your working months can end up higher than you owe on the year’s total income.
Two Jobs at Once
If you hold more than one job at the same time, your personal allowance should sit with just one employer, and the second job should be on a BR (basic rate) code. When the allowance gets applied to the wrong payroll or is split by mistake, the numbers rarely balance out on their own.
The Wrong Tax Code
Even without a job change, HMRC can issue an incorrect code based on outdated information. If deductions look off, sign in to the Check your Income Tax service on GOV.UK, review the employment and income details, and correct anything wrong or missing. HMRC asks you to wait at least 35 days after starting a new job before querying a code, because that is how long new income details take to reach their systems.
Reliefs You May Not Have Claimed
PAYE errors are only half the picture. Several allowances reduce your taxable income but rely on you claiming them, and unclaimed reliefs can be backdated up to four years.
Marriage Allowance
If you’re married or in a civil partnership and one of you earns below the £12,570 personal allowance, the lower earner can transfer £1,260 of unused allowance to their partner, cutting the recipient’s tax bill by up to £252 a year. Both partners must pay no more than the basic rate. Backdating is allowed for up to four years.
Uniforms and Work Clothing
If you buy, clean, or repair your own uniform or specialist work clothing, you can claim a flat-rate deduction. Most jobs qualify for at least £60 a year, and trades such as carpentry and construction engineering are set at £140, with some roles higher. The figure is a deduction from taxable income, so the cash you get back is that amount multiplied by your tax rate.
Professional Fees and Subscriptions
Fees paid to an approved professional body or a union, where membership is a condition of doing your job, can be deducted from taxable income. HMRC publishes a list of approved organisations whose fees qualify.
Working From Home
If your employer requires you to work from home regularly, you can claim relief on the extra household costs. The simplest route is a flat £6 per week with no receipts needed; if your actual costs are higher, you can claim the exact amount with evidence such as utility bills. You cannot claim for days you chose to work from home when an office was available. Self Assessment filers claim through their return; everyone else uses HMRC’s online service.
Higher-Rate Pension Relief
Basic-rate pension relief is given automatically. Higher-rate (40%) and additional-rate (45%) taxpayers are entitled to further relief that isn’t. You have to claim the extra 20% or 25% yourself, either through Self Assessment or by asking HMRC to adjust your tax code. This is one of the most commonly missed refunds for higher earners.
Starting Rate for Savings
If your non-savings income is below £17,570, up to £5,000 of savings interest can be taxed at 0%. Every £1 of other income above the personal allowance reduces the £5,000 band by £1, so it is most useful when you earn only a little above £12,570. It sits alongside the Personal Savings Allowance rather than replacing it.
How to Check Whether HMRC Owes You
Your Personal Tax Account
The fastest check is your Personal Tax Account on GOV.UK. Sign in with your Government Gateway credentials to see your income, tax code, and tax paid for previous years. If HMRC’s records show an overpayment, you can start the refund from there.
P800 Tax Calculation
After each tax year ends, HMRC automatically reviews PAYE records and sends a P800 calculation letter if you’ve overpaid or underpaid. These go out between June and March of the following tax year, so a delay into autumn is normal. The P800 sets out exactly how much you overpaid and how you’ll get it back.
Documents to Have Ready
Before working out whether you’re owed, gather the paperwork from each job you held in the year.
- P60: issued after the end of each tax year, showing total pay and total tax deducted for the full year with that employer. You get one per job.
- P45: given when you leave a job, showing pay and tax deducted during your time there. Your new employer uses it to set the right code, so losing it can trigger emergency tax.
- P11D: if you had benefits in kind such as a company car, private healthcare, or an interest-free loan, your employer reports their value on a P11D and must give you a copy by 6 July after the tax year ends.
On the P60 and P45, the fields to check are “Total pay in this employment” and “Total tax in this employment.” Comparing those against the tax actually due on your annual income is the quickest way to spot an overpayment.
How to Claim
If you receive a P800 saying you can claim online, sign in to your Personal Tax Account or the HMRC app and request a bank transfer. The money usually arrives within three to five working days. If the P800 says a cheque will be posted automatically, you don’t need to do anything; HMRC should send it within 14 days of the date on the letter.
If no P800 has arrived but you think you’ve overpaid, you can still claim. PAYE taxpayers can update income details and request a repayment through the Personal Tax Account, or phone HMRC’s income tax helpline. Self Assessment filers see any overpayment on their tax return and can request repayment through their account or by contacting the Self Assessment line.
Online claims are processed faster than paper forms, which take around six weeks. Outside the P800 process, HMRC often issues refunds by cheque rather than bank transfer.
Deadlines by Tax Year
You have four years from the end of the tax year in which you overpaid. After that, the year closes and the money is gone.
- 2022/23: claim by 5 April 2027
- 2023/24: claim by 5 April 2028
- 2024/25: claim by 5 April 2029
- 2025/26: claim by 5 April 2030
If you’ve been missing a relief such as Marriage Allowance or professional subscription fees for several years, backdating across all open years can be worth several hundred pounds. The four-year rule applies equally to PAYE corrections, expense claims, and relief applications, so check every open year, not only the most recent one.