Tax Code 1257L W1 Explained
Emergency tax code on a non-cumulative weekly basis — each pay period is taxed in isolation, so you may overpay early in the year.
At a glance — 1257L W1
- Personal Allowance
- £12,570
- Region
- UK-wide (rUK / Wales)
- Cumulative?
- No — emergency (W1 / M1 / X)
- Code type
- Standard L suffix
What does 1257L W1 mean?
You are entitled to the standard tax-free Personal Allowance. This is the most common tax code suffix.
Your tax-free Personal Allowance is £12,570.
This is an emergency tax code. You may be paying more tax than necessary. Contact HMRC to get your correct tax code.
How much tax will you pay on 1257L W1?
Annual income tax HMRC would deduct on 2025-26 rates for a range of salaries, assuming the full year on this code. National Insurance is additional and the same across the UK.
| Annual salary | England / Wales / NI — income tax | Effective rate | Take-home (pre-NI) |
|---|---|---|---|
| £20,000 | £1,486 | 7.4% | £18,514 |
| £30,000 | £3,486 | 11.6% | £26,514 |
| £50,000 | £7,486 | 15.0% | £42,514 |
| £80,000 | £19,432 | 24.3% | £60,568 |
| £100,000 | £27,432 | 27.4% | £72,568 |
For Scottish / rUK side-by-side, or to model your own salary, student loan and pension contributions, use the tax code checker.
Should you be on tax code 1257L W1?
Emergency codes (W1, M1, X) usually appear when starting a new job without a P45, or after a gap in employment. They can cause short-term overpayment because HMRC treats each pay period in isolation. Send your P45 or complete a Starter Checklist to switch back to a cumulative code and claim any refund through PAYE.
Related tax codes
1257L — Standard
The default HMRC tax code for most UK employees — gives you the full £12,570 tax-free Personal Allowance.
1257L M1 — Emergency (Monthly)
Emergency tax code on a non-cumulative monthly basis — each month is taxed as if it were 1/12 of the year.
S1257L — Scottish Standard
The Scottish version of the standard code. Same £12,570 allowance, but Scottish tax bands (19% / 20% / 21% / 42% / 45% / 48%) apply.
C1257L — Welsh Standard
The Welsh version of the standard code. Full £12,570 allowance with Welsh (rUK-aligned) rates.
Check your own code: enter any HMRC tax code into the free tax code checker — it decodes the letters and number, shows your Personal Allowance, and estimates your take-home using 2025-26 or 2026-27 rates.
For the full plain-English guide to every UK tax code letter, prefix and suffix, see UK Tax Codes Explained 2026-27.
Sources
Tax code rules from gov.uk/tax-codes. Income tax rates from HMRC. Effective tax figures computed live from central configuration — correct for 2025-26.