Tax code
A UK tax code tells your employer or pension provider how much tax-free pay to give you; 1257L, meaning £12,570, is the most common.
A tax code is the code HMRC gives your employer or pension provider so they take the right Income Tax from your pay. GOV.UK says “1257L is the tax code currently used for most people who have one job or pension”.
The number is your tax-free pay from that job divided by 10, so 1257L gives £12,570, the 2026/27 Personal Allowance. The letter explains the situation:
- L: the standard Personal Allowance.
- M or N: you receive or have transferred Marriage Allowance.
- BR, D0: all pay from this job taxed at 20% or 40%, often for a second job.
- 0T: no allowance on this job.
- K: untaxed income, such as a company car, is bigger than your allowance.
- S or C prefix: Scottish or Welsh rates.
A W1, M1 or X after the code marks an emergency tax code.
Example: a code of 1100L gives £11,000 tax-free instead of £12,570, so a basic rate taxpayer pays £314 more tax over the year (20% of £1,570).
Check what your code means with the UK tax code checker.