To stop emergency tax, give HMRC or your employer the income information they’re missing: sign in to your Personal Tax Account and update your employment details, call the Income Tax helpline on 0300 200 3300, or hand your new employer a P45 or a completed starter checklist.1GOV.UK. Tax Codes – If You Think Your Tax Code Is Wrong Once HMRC has what it needs, a corrected tax code goes to your employer within 15 working days, and any tax you’ve overpaid comes back through your next payslips. The longer you leave it, the longer HMRC holds money that belongs to you.
Check Your Payslip First
Emergency tax is a temporary calculation HMRC uses when it doesn’t have enough information to work out your tax-free Personal Allowance properly. Instead of spreading your allowance across the year, your employer taxes each pay period on its own, which almost always results in too much tax coming out.2GOV.UK. Emergency Tax Codes
You can confirm it from the tax code printed on your payslip. The usual emergency codes end in a suffix that flags the non-cumulative calculation:
- W1 if you’re paid weekly (for example, 1257L W1)
- M1 if you’re paid monthly (for example, 1257L M1)
- X if your pay dates vary
The 1257 reflects the current Personal Allowance of £12,570, frozen at that level through at least 2027/28.2GOV.UK. Emergency Tax Codes Scottish taxpayers see an S prefix, Welsh taxpayers a C prefix; those letters route you to the right rates but don’t change the emergency nature of the code.
Two other codes signal the same underlying problem. BR taxes everything from that job at the basic rate of 20% with no Personal Allowance applied. 0T means your allowance has been used up or your employer doesn’t have enough details to assign a proper code.3GOV.UK. What Your Tax Code Means Both can lead to serious overtaxation, especially in the early months of a new job.
Three Ways to Get Off an Emergency Code
Update Your Personal Tax Account Online
The quickest route is HMRC’s “Check your Income Tax” service inside your Personal Tax Account. Sign in, look at the employment and income details on file, and correct anything that’s wrong. If a previous job still shows as active, mark it as ended. If your estimated salary is off, fix it. These edits trigger a review, and HMRC will issue a new tax code to your employer within 15 working days.1GOV.UK. Tax Codes – If You Think Your Tax Code Is Wrong
To sign in you need a Government Gateway account. If you don’t have one, you’ll create login details during the process and may need to verify your identity using photo ID such as a passport or driving licence.4GOV.UK. Personal Tax Account: Sign In or Set Up Have your National Insurance number ready, along with your employer’s PAYE reference — the alphanumeric code printed near the top of your payslip.5GOV.UK. Your National Insurance Number
Call the Income Tax Helpline
If you’d rather speak to someone, call HMRC on 0300 200 3300.6GOV.UK. Income Tax: Enquiries The agent will verify your identity, go through the details on your payslip with you, and update your records manually. HMRC then notifies your employer of the corrected code, which should appear on your payslip within the next pay cycle or two after your employer receives it.
Give Your Employer the Right Paperwork
The single most common reason for emergency tax is starting a new job without handing over a P45 from your previous role. Without it, your employer has no record of what you’ve already earned and paid, so payroll defaults to an emergency code.2GOV.UK. Emergency Tax Codes Moving from self-employment into PAYE creates the same gap, because HMRC has no real-time payroll data to pass along.
Starting to receive taxable workplace benefits, such as a company car or private medical insurance, can also move you onto a temporary code while HMRC calculates the value of the benefit.7GOV.UK. Why Your Tax Code Might Change The same can happen when you begin drawing the State Pension alongside employment income.
If you can, chase the P45 from your previous employer. If it’s genuinely unavailable, complete HMRC’s starter checklist and give it to your new employer.8GOV.UK. Your P45, P60 and P11D Form The form is available online but doesn’t save your progress, so gather your National Insurance number and employment details before you begin.9GOV.UK. Starter Checklist if You’re Starting a New Job
Pick the Right Statement on the Starter Checklist
The checklist asks you to choose one of three statements about your situation. That choice determines the code your employer applies, so it matters:
- Statement A: this is your first job since 6 April, and you haven’t received Jobseeker’s Allowance, Employment and Support Allowance, or Incapacity Benefit. Your employer applies the full Personal Allowance on a cumulative basis, which keeps you out of emergency tax from the start.
- Statement B: you’ve had another job since 6 April but don’t have a P45, or you’ve received one of those benefits. Your employer applies the Personal Allowance on a week 1 or month 1 basis, which is effectively an emergency code, though at least you get some tax-free amount each period.
- Statement C: you have another job or receive a State, workplace, or private pension. Your employer uses code BR, taxing everything at 20% with no Personal Allowance, on the basis that the allowance is being used elsewhere.
Picking the wrong statement is one of the easiest ways to end up overtaxed for months. If this really is your only job and you haven’t claimed those benefits since April, Statement A is the right choice. Many people default to Statement B out of caution, which locks in the month 1 restriction until HMRC steps in.
How the Overpaid Tax Comes Back
In the Same Tax Year
When your employer receives an updated cumulative code from HMRC, payroll software recalculates your position for the whole year so far. Any overpayment shows up as a refund on your next payslip, usually as a negative tax figure or a separate refund line. Most people see the correction within one or two pay periods after their employer processes the new code.
After the Tax Year Ends
If 5 April passes before your code is fixed, HMRC will send you a P800 tax calculation letter setting out your total earnings, the tax you actually paid, and what you’re owed. P800s are issued between June and March of the following tax year.10GOV.UK. Tax Overpayments and Underpayments
Since May 2024, HMRC no longer pays out every P800 refund automatically. If your letter says you can claim online, you have to take that step yourself; the money sits on your tax record until you do.11GOV.UK. Tax Overpayments and Underpayments: If Your Tax Calculation Letter (P800) Says You’re Due a Refund To claim, you need the reference number from the P800 and your National Insurance number, and you can ask for a bank transfer or a cheque. Some P800s still say HMRC will post a cheque automatically. Read the wording carefully.
If You’ve Taken Money from a Pension
Pension withdrawals are the situation where emergency tax catches people out most severely. When you take your first flexible pension withdrawal, whether a single lump sum or the first regular drawdown payment, your provider will almost certainly apply emergency tax on a month 1 basis. Only 1/12th of your Personal Allowance (£1,048 in 2026/27) is treated as tax-free for that payment; the next £3,142 is taxed at 20%, the next £7,287 at 40%, and anything above £11,477 at the 45% additional rate. On a large withdrawal, the overtaxation can be dramatic.
The provider reports the payment to HMRC, which then issues a proper code for future withdrawals. If you took a one-off amount and don’t plan to take anything else from that pension before the tax year ends, PAYE won’t correct the overpayment automatically. You have to reclaim it using one of HMRC’s forms:
- Form P55 if you took only part of a pension pot and won’t take another payment before the tax year ends.
- Form P50Z if you emptied your entire pension pot and have no other taxable income.
- Form P53Z if you emptied your entire pension pot but do have other taxable income, such as PAYE wages or taxable state benefits.
- Form P53 if you took all of a small pension pot as a lump sum under the small pots rules.12GOV.UK. Claim a Tax Refund When You’ve Taken a Small Pension Lump Sum (P53)
If you file a Self Assessment return, the taxable pension income and any in-year refunds already received go on that return instead. Either way, don’t wait for the system to sort itself out. Pension emergency tax overcharges often run into hundreds or thousands of pounds and won’t come back without a claim.
Four Years to Claim
You have four years from the end of the tax year in which you overpaid to claim the money back. After that, the year is closed and HMRC will not pay out, however clear the overpayment. For the 2025/26 tax year the deadline is 5 April 2030; for 2024/25 it’s 5 April 2029. If you’ve been on an emergency code in earlier years and never checked, sign in to your Personal Tax Account and look at those years before the window closes.