In short
Your tax code tells payroll how much of your pay is tax-free and which rates to use. Most NHS staff with one job are on 1257L: the £12,570 Personal Allowance, with the last digit replaced by a letter. If your code is different, there's usually a reason, and it's worth checking.
The letters NHS staff see most
| Code | What it means |
|---|---|
| 1257L | Standard Personal Allowance, rest-of-UK tax rates |
| S1257L | Scottish income tax rates, because you live in Scotland |
| C1257L | Welsh income tax rates, because you live in Wales |
| BR | All pay from this job taxed at the basic rate, usually a second job |
| D0 | All pay from this job taxed at the higher rate, usually a second job |
| 0T | No Personal Allowance from this job, often a new job without your details |
| K | Untaxed income or benefits worth more than your allowance |
| W1, M1, X or NONCUM | An emergency code |
The S and C prefixes follow where you live, not where you work. An NHS Scotland nurse who lives in Carlisle should be on 1257L, not S1257L.
A lower number than 1257L
HMRC takes things off your allowance: company benefits such as a salary sacrifice car or medical insurance, untaxed income, or tax you owe from an earlier year. If you owe £300, for example, HMRC can take £1,500 off your allowance so a basic-rate taxpayer pays it back over the year, giving a code of 1107L. HMRC usually writes to explain how it worked your code out.
Emergency codes after starting a job
If your new employer doesn't have your previous pay details, you'll go on an emergency code, shown with W1, M1, X or NONCUM after the code. Give them your P45 from your last job, or fill in the starter checklist if you don't have one. HMRC can take up to 35 days to send the right code. If you've paid too much in the meantime, it's usually refunded through your pay once the new code is used, on your next or the following monthly pay.
Why an emergency code hurts in a back pay month
On a normal code, tax is worked out on your pay for the year so far. On an emergency code, each month is taxed on its own, as if you were paid that much every month. That matters for NHS staff because back pay, bank shifts and overtime arrive in lumps.
Say a Band 5 nurse gets £3,000 of back pay in month 6 of the tax year. On a normal code the extra tax that month is about £550, all at 20%. On an emergency code it's about £753, because part of the month's pay goes over the monthly basic-rate limit and is taxed at 40%. The difference comes back eventually, but only once your code is put right or after the end of the tax year.
Bank work and second jobs
If your bank shifts are paid as a separate job, that job normally gets BR (or D0 if your main job already uses up your basic-rate band), because your allowance is used by your main job. That's correct, not a mistake. If you've stopped one job and your allowance is still on the wrong one, ask HMRC to move it.
How to check and fix your code
Frequently Asked Questions
What tax code should I be on in the NHS?
Why is my NHS bank work on a BR code?
How long does an emergency tax code last?
Why was so much tax taken from my back pay?
Sources (checked 18 October 2026)
- Tax codes: what your tax code means (GOV.UK)
- Tax codes: emergency tax codes (GOV.UK)
- Tax codes: if you've paid too much or too little tax (GOV.UK)
- Income Tax in Scotland (GOV.UK)
- Income Tax in Wales (GOV.UK)
- Rates and thresholds for employers 2026 to 2027 (HM Revenue & Customs)
See your own payslip, with your band and shifts.
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