What an emergency tax code is
Your tax code tells your employer how much tax-free pay to give you and how to tax the rest. The standard code for 2026/27 is 1257L. Normally PAYE is cumulative: each payday it looks at your pay and tax since 6 April and puts things right, including giving you any tax-free allowance you have not used yet.
An emergency code is used until HMRC can work out the right one. The most common is 1257L followed by W1 (weekly pay), M1 (monthly pay) or X. These letters mean the code is non-cumulative: each payslip is taxed on its own, as if it were the only pay period in the year.
Why you might be on one
- You start a new job and your employer does not have a P45 from your last job.
- You start working for the first time, or after a gap, part-way through the tax year.
- You start getting a workplace or private pension.
- You start or stop receiving a company benefit, such as a company car.
- You were self-employed or claiming benefits and are now employed.
How each code works
| Code | Tax-free pay | What it means | Tax on £2,500 a month |
|---|---|---|---|
| 1257L (cumulative) | £12,570 a year, caught up | The normal code: everything evens out over the year | Depends on pay so far |
| 1257L M1, W1 or X | £1,048.25 a month | A month's allowance, with no catch-up | £290.35 |
| BR | None | Every pound at 20% | £500.00 |
| 0T | None | No allowance, normal bands | £500.00 |
In Scotland the same codes start with an S, such as S1257L M1 or SBR, and use the Scottish bands. In Wales they start with a C.
Starting a job mid-year
If you have not worked since April, you have built up unused tax-free allowance. With a cumulative code your first payslips would have little or no tax. With 1257L M1, that unused allowance is ignored.
- Tax each month on 1257L M1£290.35
- Tax due on 3 months’ pay with a cumulative code£7,500 is less than 9 months of allowance£0.00
- Overpaid after 3 payslips£871.05
Over the whole tax year this person earns £15,000. Tax due is £484.20, but six months on M1 takes £1,742.10.
BR on a first job
If your employer has no information at all, they may use BR, which taxes every pound at 20%. On a first job starting in April, that can take far too much.
- Tax each month on BR£400.00
- Correct tax on 3 months’ pay£571.05
- Overpaid after 3 payslips£628.95
The starter checklist
If you do not have a P45, your employer will ask you to complete the HMRC starter checklist. The statement you choose decides the code you start on:
| Statement | When to choose it | Starting code |
|---|---|---|
| A | This is your first job since 6 April, and you have had no taxable benefits or pension | 1257L, cumulative |
| B | This is now your only job, but you had another since 6 April or received taxable benefits | 1257L M1 or W1 |
| C | You have another job or receive a pension | BR |
Choosing the right statement is the quickest way to avoid emergency tax. If you have a P45, give it to your new employer instead: it carries your pay and tax so far, so they can use a cumulative code from the start.
Getting your code fixed
- Straight awayGive your employer your P45 or starter checklist
This is the information payroll needs to use the right code.
- Within daysCheck your code online
Use the HMRC app or your personal tax account to see your code and tell HMRC about your new job and expected pay.
- Next payslip or twoHMRC sends a new code
Your employer applies it, usually on a cumulative basis, and refunds overpaid tax through payroll.
Check the code on your payslip
Once the M1, W1 or X disappears, your code is cumulative again. If it still shows after two or three payslips, contact HMRC.
Getting overpaid tax back
- Through your pay: once a cumulative code is applied, the overpayment usually comes back in your next payslip as a tax refund.
- After the tax year: if it has not been refunded by 5 April, HMRC compares your pay and tax for the year and sends a P800 calculation, usually between June and the end of November. You can then claim the refund online.
- If you have stopped working: you can claim a refund during the year without waiting for the year to end.
Beware of refund scams
HMRC never tells you about a refund by text or email with a link. Use the HMRC app or GOV.UK directly. Refund agents can claim for you, but they charge a fee you can avoid.
Second jobs and pensions
BR is not always an emergency code. If you have two jobs, your tax-free allowance normally goes to your main job, and the second job uses BR (or D0 if your total income reaches the higher rate). That is correct, not a mistake.
The first payment from a new pension is often taxed on an emergency code too. If you take a lump sum from your pension, it can be taxed as if you will receive the same every month, leading to large overpayments you can reclaim.
Overpayment by start month
The later in the year you start, the more unused allowance an emergency code ignores, until near the end of the year when there are fewer months left to overpay. These figures assume £2,500 a month on 1257L M1, no other income since April, and a code that is never corrected.
| Started in | Overpaid by 5 April |
|---|---|
| April | £0.00 |
| June | £419.30 |
| August | £838.60 |
| October | £1,257.90 |
| December | £1,161.40 |
| February | £580.70 |
Starting in April with no other income, M1 gives the same result as a cumulative code, because you have no unused allowance from earlier months.
Emergency tax on pension withdrawals
The first taxable withdrawal from a pension under flexible access is usually taxed on an emergency code. A one-off lump sum is then taxed as if you will receive the same amount every month, which can mean thousands of pounds of overpaid tax.
You can reclaim it without waiting for the end of the tax year, using one of three HMRC forms:
- P55 if you have taken part of your pension and are not taking regular payments.
- P53Z if you have emptied your pension and have other income.
- P50Z if you have emptied your pension and have no other income.
Students, graduates and returners
Graduates starting their first job in the autumn are often on emergency codes, and are especially likely to overpay because they have unused allowance from April. Complete the starter checklist carefully: if this is your first job since 6 April, choose statement A to get the normal cumulative code straight away.
The same applies when returning to work after a career break, parental leave or time on benefits. If you claimed Jobseeker’s Allowance or Employment and Support Allowance, your P45 from the Jobcentre helps payroll get your tax right.
Weekly pay
If you are paid weekly, the emergency code is 1257L W1. Each week you get one fifty-second of the allowance, £241.90, and one fifty-second of each band. On £500 a week that means about £51.62 of tax each week.
Weekly-paid workers who start mid-year overpay in the same way as monthly-paid ones, and the fix is the same: give your employer a P45 or starter checklist, and check your code in the HMRC app.
Why HMRC uses emergency codes
Emergency codes protect against under-taxing. If payroll gave every new starter a full cumulative allowance without knowing their history, someone who had already used their allowance in an earlier job would pay too little and face a bill later. A non-cumulative code is a cautious middle ground: you get a share of the allowance each payday, but no catch-up.
The cost of that caution falls on people who have not worked earlier in the year, such as graduates, people returning from a break, and anyone between jobs for a few months. They are the ones who most often overpay, and the ones who benefit most from giving their employer accurate information early.
Spotting an emergency code on your payslip
Look for the tax code near the top of your payslip. Signs of an emergency or temporary code include:
- W1, M1 or X after the code, or a “basis” field that says non-cumulative or week 1.
- A code of BR or 0T when this is your only job.
- Tax that is much higher than a colleague on similar pay.
- Year-to-date tax that does not fall even though you started mid-year.
If you see any of these, check your code in the HMRC app, which shows the code HMRC has sent your employer, and update your income details. If the app shows the right code but your payslip does not, ask payroll when they will apply it.
What if I paid too little?
Emergency codes can lead to underpaying when you have more than one job. HMRC normally collects up to £3,000 of underpaid tax through your code the next year, spread over 12 months, rather than asking for it in one go.