How to claim an emergency tax refund in 2026/27: spot an emergency tax code, get it corrected, and reclaim overpaid tax through PAYE, P50 or your tax account.
Nobody chooses an emergency tax code. It just appears, usually on the first payslip of a new job, and quietly takes more tax than it should. The word “emergency” makes it sound alarming. It isn’t. But the money it holds back is yours, and there are faster and slower ways to get it back.
Here’s how to spot an emergency tax code, get it corrected, and claim your emergency tax refund, with a realistic view of how quickly the cash actually lands.
An emergency tax code is a temporary code HMRC applies when your new employer doesn’t have full details of your previous pay and tax, so it taxes you cautiously, often without your full personal allowance, until the right information arrives.
The most common one is 1257L W1 or 1257L M1. It still gives you the £12,570 personal allowance, but only a slice at a time, and it ignores what you earned earlier in the year. That’s what causes the overpayment.
Check the tax code on your payslip, or in the HMRC app once you’ve signed in. Three patterns tell you you’re on an emergency footing.
1257L W1 or 1257L M1 is the standard emergency code. The W1 (week 1) or M1 (month 1) means non-cumulative: payroll treats every pay period as if it’s the first of the year, so it can’t see or credit any unused allowance from earlier months.
0T gives no personal allowance at all and taxes across the normal bands. HMRC uses it when it has no starter information from you.
BR taxes everything at 20% with no allowance. It’s normal on a second job, but wrong on your only job, and there it usually means an emergency situation that needs fixing.
If your code looks like any of these and this is your main or only job, you’re probably owed an emergency tax refund.
Your personal allowance is meant to spread evenly across the tax year. A cumulative code (plain 1257L, no W1 or M1) looks at your total pay and total allowance so far and works out the right tax each time. An emergency code can’t do that.
Worked example. You start a new job in July after not working since April. That’s four months (April, May, June, July) of unused personal allowance sitting there, roughly £4,190.
On a proper cumulative code, your first payslip would credit that backlog, so you’d pay little or no tax to begin with. On 1257L M1, you get just one month’s allowance, about £1,047. If your monthly pay is £2,500, you’re taxed on £1,452 straight away, around £290 in income tax, when a cumulative code might have charged you nothing that month. That gap is your overpayment, and it builds until the code is corrected.
The fix is almost always about getting your starter details to HMRC.
If you’ve got a P45 from your last job, hand it to your new employer. It carries your pay and tax to date, which lets payroll switch you to a cumulative code.
No P45? Complete the starter checklist your employer gives you, and answer honestly. If you tick statement A (this is your first job since 6 April, or you’ve had no other income), that’s usually enough for HMRC to issue a cumulative 1257L.
Once the correct code is in place, the emergency tax refund often takes care of itself. PAYE recalculates using your full year-to-date allowance and pushes the overpaid tax back to you through your wages, normally within a payslip or two. You don’t have to fill in anything.
How quickly you see the money depends on your situation. Here’s what I’d do in each case.
Still working, code now corrected. Do nothing extra. The refund lands in your next one or two payslips automatically. This is the most common path and the least effort.
Stopped working and won’t earn again this tax year. Don’t wait for April. Submit form P50 through your Personal Tax Account. This tells HMRC you’re done for the year, and they refund the overpayment directly, usually within a few weeks. This is the classic route for anyone leaving a job, going travelling, or heading back to study.
You want to chase it online. Sign in to your Personal Tax Account or the HMRC app, check the current-year estimate, and if HMRC has already calculated a refund you can request it as a bank transfer. Approved online refunds typically reach your account in about five working days.
That’s where the “seven days” idea comes from. In the best case, a P50 or an online refund request, you really can have the money within a week or so. But if you’re relying on payroll to correct a fresh emergency code, be realistic: it moves at the speed of your pay cycle, so a monthly-paid job might take until next payday.
If you never get round to it and the tax year closes on 5 April with tax still overpaid, HMRC catches it anyway. After year-end it runs a reconciliation, and if you’ve overpaid it sends a P800 calculation explaining the refund and how to claim it, often with a straight-to-bank option. So an emergency tax refund is rarely lost. It’s just slower if you leave it to the automatic sweep than if you claim it yourself.
The size of an emergency tax refund depends on how much allowance the code failed to give you, and for how long. A few realistic scenarios show the range.
One month on an emergency code, then fixed. If you started a job mid-year on 1257L M1 and it corrected after a single payslip, you might be owed a month or two of over-deducted tax, often somewhere between £100 and £400, refunded through your wages once the cumulative code lands.
Several months on 0T before anyone noticed. This is worse, because 0T gives no allowance at all. On a £2,500-a-month wage, 0T charges 20% on the whole £2,500 (£500) instead of on the £1,452 above your monthly allowance (£290). That’s roughly £210 a month too much, so four months could leave you owed around £840.
A one-off BR code on your only job. BR taxes everything at 20% with no allowance. On modest pay that’s a similar overcharge to 0T, and every month of it is reclaimable.
The point is that the longer the wrong code runs, the more it’s worth checking. A quick look in the HMRC app can be the difference between spotting it in week two and finding out next April.
The best emergency tax refund is the one you never have to claim. Two habits prevent most of it.
Hand your P45 to a new employer straight away, or complete the starter checklist on your first day rather than letting it slide. That single piece of paper is what stops the emergency code appearing in the first place.
And check your tax code on your first payslip of any new job. If it ends in W1 or M1, or shows 0T or BR when this is your only job, you’ve caught it early, when a correction sorts it in a payslip or two rather than months later.
The emergency tax rules are unchanged for 2026/27. The personal allowance is still £12,570, the codes still behave the same way, and P45s, starter checklists and P50 all work as before.
The one shift, from April 2026, is that HMRC now issues most tax code notices online rather than by post. That’s a small win for anyone chasing an emergency tax refund: when your correct code is issued, you’ll see it in your HMRC account straight away, instead of waiting for a letter. Keep an eye on the app after starting a new job, and you’ll spot the correction the moment it happens.
1257L W1, 1257L M1, 0T, BR on a main job) tax you cautiously and often overcharge you.If you want to check whether the tax on your payslip actually looks like an overpayment, before you chase HMRC, the NetPay app shows what your correct take-home should be on a normal code, so an emergency deduction is easy to spot. Free to download.
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It depends on the route. If you're still employed, your refund usually comes through your next one or two payslips once HMRC issues the correct cumulative code. If you've stopped working, a P50 claim is typically processed within a few weeks. A refund requested online through your Personal Tax Account can reach your bank in about five working days once HMRC has approved it.
Check the code on your payslip or in the HMRC app. Emergency codes usually end in W1 or M1, such as 1257L W1. You might also see 0T or BR if HMRC has no starter information for you. Any of these mean you may be overpaying and can reclaim it.
Often, yes. Once your correct cumulative tax code is in place, PAYE recalculates and refunds any overpayment through your wages, usually within a payslip or two. If the tax year ends before it's sorted, HMRC issues a P800 calculation and refunds the difference automatically. You only need to claim manually if you've stopped working.
Yes. Sign in to your Personal Tax Account or the HMRC app to check your code and prompt a correction. If you've stopped working for the rest of the tax year, submit form P50 to claim the refund straight away rather than waiting for year-end reconciliation.
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NetPay UK works out your real net pay after tax, NI, pension and salary sacrifice, for hourly, shift and variable-income workers. Free to download.
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A note on financial advice: NetPay UK calculates take-home pay based on official HMRC tax rules. This article reflects rules in force at the time of publication (19 July 2026). Tax rules change. For complex situations, consult a qualified UK accountant or visit gov.uk/income-tax.
