What to Do If You've Been Taxed Too Much This Year

Overpaying tax is more common than most people realise, especially if you have changed jobs, worked part of the year, retired, drawn from a pension, or started a new income stream. The good news is that HMRC usually owes you the money back, and there are clear routes to claim it.

This guide explains how to tell if you have been taxed too much, what causes it, and exactly how to get your money back, whether you are on PAYE or Self Assessment. Before you start, it is worth running your figures through our Income Tax Calculator so you have a benchmark for what your take-home pay should actually be.

Important update: since 31 May 2024, HMRC no longer posts automatic refund cheques in most cases. If you are owed money, you usually have to claim it yourself online or through the HMRC app. If you do nothing, the refund simply sits on your tax record until you act, or until the time limit runs out.

Why You Might Have Been Taxed Too Much

Overpayments rarely mean you did anything wrong. They usually happen because PAYE works in real time and cannot always keep up with changes in your circumstances. The most common causes are:

• Emergency tax code: Starting a job without handing over a P45 often puts you on an emergency code, which can ignore part of your tax-free allowance. See our guide on understanding emergency tax codes and how to get them fixed.
• Changing jobs mid-year: If your new employer does not get your previous pay and tax details in time, your allowance can be applied incorrectly.
• A wrong tax code: If HMRC holds outdated information, your code can be too low. Our list of tax codes and what they mean helps you decode yours.
• Working part of the year: Leaving work early, taking a career break, or starting late often means your full personal allowance was not spread across the year.
• A second job or multiple incomes: Your personal allowance may not have been split correctly between employers. See second job tax.
• Pension withdrawals: One-off or flexible pension drawdowns are frequently taxed on a Month-1 basis, which almost always overcharges you up front.
• Unclaimed allowances or expenses: Marriage Allowance, working-from-home relief, uniform costs, or professional subscriptions can all reduce your bill if claimed.

You can use our Income Tax Calculator to quickly check whether the tax coming out of your pay matches what you should actually owe.

Signs You May Have Overpaid

Before going through the formal checks, these are the quick warning signs that you might be due a refund:

• Your tax code ends in M1, W1 or X (an emergency or non-cumulative code).
• Your code is BR, D0 or 0T on your main job, when it should be a standard allowance code.
• Your take-home pay dropped suddenly without a pay change. Our guide on why your take-home pay is lower than expected walks through the usual culprits.
• You started a new job partway through the year, or had a gap between jobs.
• You took money out of a pension as a lump sum.
• You received a P800 letter from HMRC stating you have overpaid.

For a deeper understanding of how tax codes affect your pay, our 1257L tax code guide explains the standard code in detail.

Step 1: Check Your Payslip or P60

Start by reviewing your tax documents:

• Payslip: Look for your tax code (for example, 1257L) and your year-to-date tax figure. Our guide on understanding your PAYE payslip explains each line.
• P60: A summary of your total pay and tax for the year, issued by your employer after 5 April. See what a P60 form is and why it matters.
• P45: Issued when you leave a job, showing income and tax paid to date. The difference between the two is covered in P45 vs P60.

If your tax code contains M1 or W1, you have probably been placed on an emergency code, which is one of the most common reasons for overpayment. To confirm whether your code is correct, read how to check and correct your HMRC tax code.

Step 2: Log in to Your HMRC Personal Tax Account

Go to GOV.UK and sign in to your Personal Tax Account (or use the HMRC app). From there, you can:

• Check your current and past tax code notices
• See how HMRC calculated your deductions
• Review your full income and tax history for the year
• Update your employment and income information

If the system shows an overpayment, you can usually claim your refund online within minutes. If it does not show one but you still think you have overpaid, you may need to make a separate claim, because HMRC only spots what its records reveal.

Step 3: Understand How Refunds Are Processed

There are two broad ways a refund reaches you.

1. Automatic review (P800 or Simple Assessment)

• After the tax year ends, HMRC reconciles your PAYE records, usually between June and November.
• If you have overpaid, it sends a P800 tax calculation.
• You then claim online for a bank transfer, which typically arrives within 5 working days. Since 31 May 2024 the refund is no longer sent automatically by cheque, so the claim step matters.

2. Manual claim

For situations HMRC does not detect automatically, such as leaving work mid-year, a pension withdrawal, or unclaimed expenses, you submit the correct claim form yourself rather than waiting for a P800.

Step 4: Choose the Right Refund Route

If your refund relates to a pension drawdown, our Pension Tax Calculator helps you estimate how much tax should have applied. If you left work partway through the year, the Part-Year Employment Calculator shows what your correct annual position should look like.

Step 5: How Long the Refund Takes

Delays can happen if information is missing, identity checks are needed, or figures conflict with employer RTI submissions.

How Far Back Can You Claim?

You can reclaim overpaid tax for the current tax year plus the four previous tax years. After that, the entitlement is lost. As of 2026, that means you can still claim back to the 2021/22 tax year, but the deadline to claim 2021/22 is 5 April 2026. Later years remain open for longer.

If you think you may have overpaid in earlier years, it is worth checking now rather than waiting, because each tax year has its own hard deadline and HMRC does not send reminders before the money lapses.

For help with Self Assessment overpayments, our Self Assessment complete guide explains the amendment process.

Worked Example: Tax Refund in Action

Emergency code refund: Ben changes jobs in July, and his new employer does not receive his P45 in time. He is put on an emergency code (1257L M1) and ends up paying around £500 more than he should. In October, Ben logs in to his HMRC Personal Tax Account, sees the overpayment, and claims online. The bank transfer lands within two weeks, and his code is corrected so it does not happen again.

Pension withdrawal refund: Priya takes a £12,000 lump sum from her pension in May. HMRC applies a Month-1 emergency code and taxes the withdrawal as if she would take that amount every month, overcharging her by roughly £1,800. Because this is a one-off withdrawal, HMRC will not always catch it automatically, so Priya submits a P55 form and receives the difference back within a few weeks.

For a detailed walkthrough of the refund process, our step-by-step tax refund guide covers every method in full.

Overpaid Through Self Assessment?

If you complete a Self Assessment tax return, overpayments are handled differently. You either claim the refund directly within the return, or you correct an earlier return through an amendment. You normally have until 12 months after the 31 January filing deadline to amend a return, so for the 2024/25 return you have until 31 January 2027. Refunds claimed this way are usually paid by bank transfer within a couple of weeks if your account details are on file.

Step 6: Prevent Overpaying Next Year

• Check your tax code every few months, especially after any change in circumstances. Our guide on why HMRC changes tax codes mid-year explains the common triggers.
• Always hand your P45 to a new employer, or complete the new starter checklist if you do not have one.
• Tell HMRC if you start a second job or change income sources, so your personal allowance is split correctly.
• Keep your P45, P60 and payslips together as evidence.
• Run your numbers through our Income Tax Calculator and National Insurance Calculator a few times a year.

Common Tax Overpayment Scenarios

Watch Out for Refund Scams

Tax refunds are a favourite target for fraudsters, and fake messages have become more convincing. Keep these rules in mind:

• A genuine P800 only arrives by post or appears in your HMRC online account. HMRC will never text, email or WhatsApp you a refund link.
• HMRC will never ask for your bank details, card number, PIN or passwords by message.
• Always go to GOV.UK directly rather than clicking links, and check the address ends in .gov.uk.
• If in doubt, contact HMRC on 0300 200 3300 to confirm whether a refund is real.

Common Mistakes to Avoid

• Ignoring an emergency code instead of getting it corrected early.
• Assuming all refunds are automatic. Since 31 May 2024, most need an active claim.
• Falling for scam texts or emails promising a quick rebate.
• Not keeping records. Your P45, P60 and payslips are vital proof.
• Leaving old years unclaimed until the four-year window closes.

Key Takeaways

• Overpaid tax is usually refundable, either through a P800 review or your own claim.
• Since 31 May 2024, refunds are no longer sent automatically; you generally have to claim.
• Check your payslip, P60 and HMRC Personal Tax Account regularly.
• You can claim back up to four previous tax years, so do not delay.
• Use our Income Tax Calculator to verify your figures, and always use official GOV.UK services.

Final Thoughts

Being taxed too much is frustrating, but it is usually fixable. The key is to check your tax code, payslip, and P60 regularly. If you spot an issue, act quickly. Since May 2024, most refunds require an active claim, so you cannot assume HMRC will automatically send you the money.

Use your Personal Tax Account to check your record and claim refunds online. For complex situations like pension withdrawals or Self Assessment overpayments, use the correct forms and routes outlined in this guide.

If you are unsure about anything, check the official GOV.UK website or contact HMRC directly. Avoid clicking on unsolicited refund links and never share your bank details with anyone claiming to be HMRC by text or email.

All information in this guide is based on official HMRC and GOV.UK sources. Readers should verify current procedures directly with HMRC before making decisions, as rules may change after publication.