The emergency tax percentage in the UK is 20%, 40%, or 45%, depending on which temporary code your employer’s payroll uses. Most people on emergency tax pay 20% on earnings above a reduced monthly slice of the personal allowance. A smaller group loses the allowance entirely and pays 20% from the first pound, with 40% and 45% kicking in at the usual higher-rate thresholds. It is temporary, and the overpayment usually comes back to you inside the same tax year.
The Three Emergency Codes and What Each Takes
There isn’t one flat emergency rate. The percentage depends on which of these codes lands on your payslip.
1257L W1, M1, or X. This is the most common emergency code. You keep a personal allowance of £12,570, but payroll calculates your tax one pay period at a time instead of across the whole year. Each month you get roughly £1,048 tax-free (one-twelfth of the allowance) and pay 20% on everything above that. Because the system ignores what you earned in earlier months, it can’t spread unused allowance across the year, which is what causes the overpayment.
BR. Every pound from that job is taxed at a flat 20%, with no personal allowance applied. HMRC usually issues this when it thinks another source of income is already using your allowance.
0T. Your personal allowance is set to zero and the standard rate bands still apply. You pay 20% on the first £37,700 of taxable income, 40% between £37,701 and £125,140, and 45% above £125,140. This is the harshest emergency code and typically appears when your employer has no starter information for you at all.
The underlying income tax rates for 2025/26 are 20% basic, 40% higher, and 45% additional, with the personal allowance held at £12,570.1GOV.UK. Income Tax Rates and Personal Allowances
If You Live in Scotland
Scottish emergency codes start with an “S” (for example, S1257L M1 or S0T), and Scotland sets its own income tax rates. There are six rate bands rather than three, starting at 19% and reaching 48% at the top, with an intermediate rate of 21% and an advanced rate of 45% that apply at lower thresholds than the equivalent UK-wide bands. On an S0T code, the higher rates can bite earlier than you might expect.
Why You’re on Emergency Tax
Emergency tax almost always comes down to HMRC not having enough information to give you a proper code.
Starting a new job without a P45 from your previous employer is the biggest single cause. The P45 carries your pay to date, the tax you have already paid that year, and your most recent code; without it, payroll has to guess.2GOV.UK. Tax Codes – Emergency Tax Codes The same happens if you are entering the workforce for the first time, coming back from self-employment, or returning after a long gap with no PAYE records.
Sometimes it is purely administrative. Your employer may have filed everything correctly, but HMRC hasn’t yet processed it and sent a coding notice back. A missing or wrong National Insurance number will also stall things, because HMRC needs it to match you to your tax record.
How to Get Off Emergency Tax
The fastest fix is to give your new employer your P45. Hand over Parts 2 and 3 and keep Part 1a.3GOV.UK. Your P45, P60 and P11D Form – P45
If you don’t have one, your employer should ask you to complete a Starter Checklist.4GOV.UK. Starter Checklist if Youre Starting a New Job It asks you to pick one of three statements, and each triggers a different code:
- 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 this tax year. Your employer applies the full personal allowance on a cumulative basis.
- Statement B: you’ve had another job since 6 April but don’t have a P45, or you’ve received one of those benefits. You get the personal allowance, but on a non-cumulative (week 1/month 1) basis.
- Statement C: you currently have another job or receive a state, workplace, or private pension. Your employer applies the BR code, taxing all earnings at 20% with no personal allowance.
Picking the wrong statement is a common error. Choosing C when A applies means you lose your entire tax-free allowance on that job until HMRC untangles it.5HM Revenue and Customs. Starter Checklist
You don’t have to wait for HMRC. Sign in to the Check Your Income Tax service through your HMRC online account or the HMRC app, review your employment details, estimated income, and tax code, and update anything wrong or missing. You can also phone the income tax helpline and ask an adviser to change your code.6GOV.UK. Tax Codes: If You Think Your Tax Code Is Wrong HMRC’s official timeframe for issuing a new coding notice to you and your employer is up to 15 working days, though online updates often go through faster.
Getting the Overpayment Back
Once your employer receives the corrected coding notice and your code switches from non-cumulative to cumulative, payroll recalculates your tax for the year to date. Any overpayment usually comes back as a credit on your next payslip, without a separate claim. If you were stuck on 1257L M1 for several months, that refund can be substantial, because the system finally credits the unused allowance from earlier pay periods.
If the tax year ends before your code is fixed, HMRC’s P800 reconciliation should pick up the overpayment. HMRC compares what you actually earned against what you paid and issues a P800 tax calculation. Since May 2024, HMRC no longer automatically posts repayment cheques for all P800 refunds, so you may need to claim yours through your online account or by post once the P800 letter arrives.7GOV.UK. Check How to Claim a Tax Refund If you do nothing, the money can sit unclaimed. Most P800 calculations go out from July onwards, so check your account then if you think you’re owed a refund.