What does tax code 1257L mean?
1257L is the standard tax code for most UK employees — here's exactly what the numbers and letter mean, and when yours might look different.
Written by Jack Dev · Last updated 2 October 2026
Breaking down the numbers
Your tax code looks cryptic, but it's really just an instruction to your employer: here's how much of this person's pay to leave untaxed. Take the number in 1257L, multiply by 10, and you've got your tax-free Personal Allowance for the year — £12,570, which happens to be exactly the standard allowance for 2026/27. Change the number and the allowance changes with it: 1000L would mean £10,000 tax-free instead.
1257L is also just about the most common code in the country — the default for anyone with one job, no taxable perks, and no history of under- or overpaid tax to square up.
What the letter means
The letter does a different job — it flags something specific to HMRC's system, and it shows up on your payslip too. L is the boring-but-common one: standard allowance, nothing unusual going on.
- L — Standard Personal Allowance, no adjustments
- M — You're receiving Marriage Allowance transferred from your partner
- N — You've transferred part of your Marriage Allowance to your partner
- T — Your code includes items HMRC needs to review further
- K — Your allowance is negative, meaning extra income is added to what's taxed, usually because of benefits or previous underpaid tax that exceeds your allowance
- BR — All your income from this source is taxed at the basic rate (20%), with no Personal Allowance applied — common for a second job
- D0 / D1 — All income taxed at the higher (40%) or additional (45%) rate, again with no allowance — also typically a second job or pension
- 0T — No Personal Allowance at all; every pound is taxed through the normal bands
Why your code might not be 1257L
Codes drift away from 1257L for a handful of reasons: a company car or private medical insurance eating into your allowance, an old tax bill being clawed back through your current pay, having more than one income source (only one of which usually gets the full allowance), or claiming Marriage Allowance.
Live in Scotland and you'll see an S stuck on the front (S1257L); in Wales, a C (C1257L). Same £12,570 allowance underneath — the letter's just telling HMRC which set of bands to apply.
Checking your own code
You'll find your code on your payslip, your P60, or any coding notice HMRC sends you directly. If it looks off — you've changed jobs, lost a benefit, picked up a second role — it's worth flagging to HMRC, because a wrong code quietly means you're paying too much or too little all year without realising.
Curious what a specific code actually means? Drop it into our Tax Code Checker. Or if you want to see the real-money difference it makes, put your own code into the Salary Calculator and compare it against the standard 1257L.
Frequently asked questions
It's the default for most employees with one job and nothing unusual going on — the full £12,570 Personal Allowance for 2026/27. Your own code can still differ depending on your circumstances.
Your allowance has gone negative — usually because taxable benefits or old underpaid tax outweigh your Personal Allowance, so extra income gets added to what's taxed rather than taken off it.
Because your Personal Allowance has already been allocated to your main job's tax code, so everything from the second job is taxed at a flat 20% with no allowance of its own.
This guide is general information, not financial or tax advice — check GOV.UK or a qualified adviser for anything that affects a real financial decision.