C1257L Tax Code: The Complete 2025-26 Guide
If you live in Wales and your payslip shows C1257L, you are on the standard Welsh tax code for 2025-26. It works identically to the England code 1257L — giving you a Personal Allowance of £12,570 — but the C prefix signals to HMRC that you are a Welsh resident subject to the Welsh Rates of Income Tax (WRIT).
Breaking down C1257L
The code has two components:
- C: Cymru — Welsh resident. HMRC uses this to account for the Welsh government's share of income tax revenue collected from Welsh taxpayers.
- 1257: Your tax-free Personal Allowance is £12,570 (the number × £10).
- L: You are entitled to the standard Personal Allowance with no adjustments.
Welsh Rates of Income Tax 2025-26
The Senedd (Welsh Parliament) sets the Welsh Rates of Income Tax each year. For 2025-26, these are identical to England's rates:
| Band | Income range | Rate |
|---|---|---|
| Personal Allowance | Up to £12,570 | 0% |
| Basic Rate | £12,571–£50,270 | 20% |
| Higher Rate | £50,271–£125,140 | 40% |
| Additional Rate | Over £125,140 | 45% |
In practice, Welsh taxpayers on C1257L pay exactly the same income tax as English taxpayers on 1257L at equivalent salaries. The distinction matters for government revenue distribution, not for the amount on your payslip.
Take-home pay on C1257L: common salaries
| Gross salary | Income tax | National Insurance | Take-home (year) | Take-home (month) |
|---|---|---|---|---|
| £20,000 | £1,486 | £594 | £17,920 | £1,493 |
| £25,000 | £2,486 | £994 | £21,520 | £1,793 |
| £30,000 | £3,486 | £1,394 | £25,120 | £2,093 |
| £35,000 | £4,486 | £1,794 | £28,720 | £2,393 |
| £40,000 | £5,486 | £2,194 | £32,320 | £2,693 |
| £50,000 | £7,486 | £2,994 | £39,520 | £3,293 |
Why does my code show C rather than just 1257L?
HMRC determines your tax residency based on where you live, not where you work. If your main home is in Wales, you will automatically receive the C prefix. You do not apply for it — HMRC assigns it based on your address. This matters because the Welsh government receives a portion of the income tax revenue from Welsh taxpayers.
When might C1257L change?
Your code may be adjusted in specific circumstances:
- You receive a benefit in kind (e.g. company car) — your code will be reduced to collect that tax
- You claim the Marriage Allowance — your code becomes CM or CN
- You move to a different region — HMRC will update to remove or add the C prefix
- You have untaxed income — the number portion of the code will be reduced
Frequently asked questions
What does C1257L mean on my payslip?
C1257L is the standard Welsh tax code. C = Welsh resident, 1257 = £12,570 Personal Allowance, L = standard allowance. You pay 0% on the first £12,570, then 20% up to £50,270, then 40%.
Is C1257L the same as 1257L?
Yes, the take-home pay is identical. The C prefix only affects how HMRC accounts for the revenue — it goes to the Welsh government rather than HM Treasury.
I moved from England to Wales — will my code change from 1257L to C1257L?
Yes. Once HMRC updates your address to Wales, your code will be changed to C1257L. This usually happens at the start of the next tax year, though it can be updated mid-year. Your take-home pay will not change.
What if my C1257L code is wrong?
Contact HMRC on 0300 200 3300 or use your Personal Tax Account at gov.uk. Common causes of an incorrect code: an incorrect address on record, a benefit in kind that has changed, or a previous year's underpaid tax being collected.