Emergency tax: how it works and how to get your money back

Emergency tax means your tax is worked out one payday at a time

Emergency tax is Income Tax worked out on each week's or month's pay on its own, ignoring what you have earned and paid earlier in the tax year. According to GOV.UK, you are on an emergency tax code if your code ends in W1 (paid weekly), M1 (paid monthly) or X (pay dates vary), and some payroll software shows NONCUM instead.

According to HMRC's rates and thresholds for employers, the emergency tax codes from 6 April 2026 are 1257L W1, 1257L M1 and 1257L X. You may also see an S prefix if you pay Scottish Income Tax or a C prefix for Welsh Income Tax.

Emergency tax is not a special higher rate. You still get the standard Personal Allowance of £12,570, but only one twelfth of it (£1,047.50) each month or one fifty-second each week. GOV.UK says you are taxed "as if you're paid that amount every week or month of the year". That is correct if you have worked all year at the same pay, and too much if you earned little or nothing before the job started.

This guide covers emergency codes and getting the money back. For every other code problem, such as 0T or BR on your only job or a K code, see why your tax code might be wrong. To see what your own code means and what it takes from each payslip, use the tax code checker, which compares an emergency code with the normal cumulative basis.

When emergency tax is used: a new job without a P45, the starter checklist, or a new pension

You are put on emergency tax when the payer does not have your pay and tax details for the year so far. According to GOV.UK, this happens most often when you start a new job and your new employer does not have a P45 from your previous job.

Without a P45, your employer asks you to fill in the starter checklist, which replaced form P46. The statement you pick decides your first code. According to HMRC's PAYE Manual (PAYE61030), the codes are:

Picking the statement that is true for you matters. A student starting their first job since April who ticks A gets the whole year's allowance so far; the same person on 1257L M1 gets one month's allowance per payslip.

GOV.UK lists two other triggers. You can be put on an emergency code when you start getting company benefits or the State Pension, and then it lasts until the end of the tax year. And, according to HMRC's PAYE Manual (PAYE76170), a pension scheme paying your first flexible withdrawal uses the emergency code on a month 1 basis unless you give it a P45 dated in the current tax year.

How much extra emergency tax takes: a first payslip worked through

Emergency tax took £290.50 from a first £2,500 monthly payslip in our example, where the normal cumulative code would have taken nothing. The figures come from the site's tax code engine, using 2026/27 rates.

The situation. You leave university in June 2026, earn nothing from 6 April, and start a job on £30,000 a year in September 2026. Your first monthly pay of £2,500 falls in tax month 6 (6 September to 5 October). You have no P45.

On 1257L M1 the sum is £2,500 minus £1,047.50, leaving £1,452.50 taxed at 20%. On the cumulative basis, six months of allowance (£6,285) exceeds the £2,500 earned, so no tax is due.

If the code were never corrected, 7 months at £2,500 on 1257L M1 would cost £2,033.50 in tax, against £986 on the cumulative basis for £17,500 of pay: £1,047.50 too much. To reproduce this, enter 1257L M1, £30,000 a year, paid monthly, starting in September, in the tax code checker. The engine reads 1257 as £12,570 exactly, so HMRC's payroll tables can differ by a few pounds.

Emergency tax can also take too little. If you earned well earlier in the year, your old job has already used much of your allowance, and the new job gives you another month's worth each payday. GOV.UK says that if you have not paid enough tax, you stay on the emergency code until you have paid the correct tax for the year.

National Insurance is not affected. For most employees it is worked out on each pay period, using thresholds of £242 a week or £1,048 a month for 2026/27, according to HMRC, so there is no National Insurance refund when your code is fixed.

Emergency tax on a pension withdrawal can take thousands

Emergency tax on a first flexible pension withdrawal treats one large payment as a month's pay repeated 12 times, which pushes much of it into the 40% and 45% bands. According to HMRC's PAYE Manual (PAYE76170), the scheme uses "the emergency tax code on a month 1 basis against the first payment" unless you have a P45 from the current tax year, and HMRC then issues a code for later payments.

Worked example. You take £40,000 from a pension pot you have not touched before. According to GOV.UK you can usually take up to 25% tax-free, so £10,000 is tax-free and £30,000 is taxable. On 1257L M1, the site's tax code engine gives:

If the £30,000 is your only income for 2026/27, the tax actually due is £3,486 (20% on £17,430 above the £12,570 allowance), so £8,392.88 is overpaid. To check this in the tax code checker, enter 1257L M1 with £360,000 a year paid monthly (12 times £30,000); the monthly tax is the emergency deduction.

Because HMRC issues a proper code after the first payment, some people take a small first withdrawal so that the code is in place before the large one. The ways to reclaim an overpayment are set out below.

How emergency tax is refunded through your pay once the code is corrected

Emergency tax is usually refunded through your pay, automatically, once HMRC sends your employer a corrected code on the cumulative basis. According to GOV.UK, HMRC updates your code when it has details from your new and previous employers, which can take up to 35 days from your start date.

When your employer gets the new code, GOV.UK says it should be used on your next or the following payslip if you are paid monthly, and on your third payslip if you are paid weekly. Under the cumulative basis your employer looks at all your pay and tax since 6 April, so the overpaid tax comes back as a lower or negative tax figure on that payslip. HMRC's PAYE Manual (PAYE11090) says the employer "deducts more or less tax, or makes a refund" as needed.

The quickest fix is a P45. Give your new employer the P45 from your last job, or ask your old employer for one if you did not get it. According to GOV.UK, if you started more than 35 days ago and your code still looks wrong, update your details yourself rather than waiting.

An emergency code that follows new company benefits or the State Pension is different: GOV.UK says it stays until the end of the tax year, and you move to a normal code from the new tax year.

Give HMRC your details through the HMRC app or your personal tax account

You can give HMRC the details it needs to fix an emergency code through the HMRC app or the Check your Income Tax service in your personal tax account. According to GOV.UK, the service lets you check your tax code and Personal Allowance, see your estimated income from each job and pension, and update your employer or pension provider details.

1. Sign in to the HMRC app or your personal tax account.
2. Check that your new job or pension is listed, with the right employer and start date.
3. Correct the estimated pay for the job if it is wrong, and end any job you have left.
4. Check that your old job shows an end date; if not, ask your old employer for your P45.

According to GOV.UK, if your code needs to change, HMRC will tell you and your employer the new code within 15 working days. If you cannot use the online service, you can contact HMRC, but GOV.UK asks you to wait 35 days after starting a new job first, to give HMRC time to receive your income details.

If payroll does not refund it: the P800 after the tax year ends

Emergency tax that is not refunded through your pay is picked up after the tax year ends on 5 April. According to GOV.UK, HMRC then checks your income details and sends a tax calculation letter, known as a P800, between June and March of the following tax year.

For the 2026/27 tax year, which ends on 5 April 2027, that means a letter between June 2027 and March 2028. If the P800 says you can claim online, GOV.UK says you get the money within 5 working days by bank transfer. If it says you will get a cheque, it arrives within 14 days of the date on the letter. You can also claim through your personal tax account or the HMRC app.

You do not have to wait if you have stopped working. According to GOV.UK, you can claim an in-year refund on form P50 if you have been out of work for 4 weeks or more and are not claiming taxable benefits, have retired without a pension from your old employer, or have returned to full-time study. If you expect to start a new job within 4 weeks, give that employer your P45 instead and the refund comes through your pay.

Pension withdrawals: claim the refund back with P55, P53Z or P50Z

You can reclaim emergency tax on a flexible pension withdrawal in the same tax year using one of three HMRC forms, instead of waiting for a P800. Which one depends on whether you emptied the pot and whether you have other income.

According to GOV.UK, you can claim each of these online by signing in, or print and post the form. For P53Z and P50Z you need parts 2 and 3 of the P45 your pension provider sends when the pot is emptied. For P50Z, GOV.UK says to send the form only once 4 weeks have passed since you stopped work or finished your pension, and that a reply may take 14 days.

P55 applies only if the pension provider cannot make the refund itself and you will take no more payments before 5 April. If you will take further payments in the same tax year, HMRC issues a tax code for them after the first payment, according to HMRC's PAYE Manual (PAYE76170), and the provider adjusts the tax on those payments.

What to do next if you are on an emergency tax code

If your payslip shows W1, M1, X or NONCUM after your code, work through these steps in order:

1. Check the payslip in the tax code checker to see how much the emergency code is taking compared with the cumulative basis.
2. Hand over your P45, or ask your previous employer for it. If you have none, make sure your starter checklist statement is correct.
3. Update your details in the HMRC app or your personal tax account once your first pay has gone through.
4. Watch the next 2 payslips (3 if weekly) for the new code and the refund.
5. After 35 days, contact HMRC if nothing has changed.
6. For a pension withdrawal, claim on P55, P53Z or P50Z rather than waiting for the end of the tax year.

For the full list of UK codes and what each letter means for 2026/27, see the tax code hub.