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Tax code 1257L is by far the most common UK tax code. It tells your employer to give you the full £12,570 personal allowance against your salary. Here's exactly what each digit means and when yours might be different.
How tax code 1257l explained works in 2025/26
Decoding 1257L:
- 1257 — your tax-free allowance ÷ 10. So 1257 × 10 = £12,570 of tax-free pay per year.
- L — you're entitled to the standard personal allowance with no adjustments. Most common suffix.
Your employer divides £12,570 by your pay frequency:
- Monthly: £12,570 ÷ 12 = £1,047.50/month tax-free
- Weekly: £12,570 ÷ 52 = £241.73/week tax-free
- Fortnightly: £483.46 tax-free
Common 1257L variants:
- 1257L M1 or 1257L W1 — emergency/non-cumulative version. Each pay period treated as month 1.
- S1257L — Scottish taxpayer (S prefix). Same allowance, but Scottish bands apply.
- C1257L — Welsh taxpayer (C for Cymru). Identical bands to England in 2025/26.
- 1257LX — sometimes used for emergency code on payslips (X = M1/W1 marker).
Other suffixes you might see: M (received Marriage Allowance from spouse, code becomes 1383M), N (transferred Marriage Allowance to spouse, code becomes 1131N), T (other adjustments — usually high earners with PA taper).
Worked example: £25,000 on 1257L cumulative
Smooth monthly tax: £12,570/12 = £1,047.50 tax-free per month. Tax £207.17/month, NI £82.87/month. Same as annual÷12.
Gross: £25,000 → Take-home: £21,519.60/year (£1,793.30/month)
Worked example: £25,000 on 1257L M1 (emergency)
First payslip Jan: applies £1,047.50 PA assuming first month. If you started Sept (month 6), miss out on previous 5 months' allowances initially — corrected at year end.
Gross: £25,000 → Take-home: £21,519.60/year (£1,793.30/month)
Worked example: £35,000 on S1257L (Scottish)
Same £12,570 PA, but Scottish 6-band rates: starter 19% / basic 20% / intermediate 21%. Tax £4,547.
Gross: £35,000 → Take-home: £28,658.60/year (£2,388.22/month)
Frequently asked questions
Official UK Sources
- GOV.UK — Tax codes
- GOV.UK — Letters in your tax code
- GOV.UK — Personal Tax Account
- GOV.UK — Income Tax rates and PA
Last reviewed: May 2026 against HMRC 2025/26 rates.