PAYE employees & pensioners
What does my tax code mean?
Your tax code is the short string of numbers and letters on your payslip — like 1257L, BR or K497 — that tells your employer how much tax-free pay to give you and how much tax to take. Get it wrong and you quietly overpay (or underpay) for months. Type yours in below to see exactly what it means, the tax-free pay it gives you, and — if you add your salary — roughly how much tax it collects and whether that looks right.
Check your tax code
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How a tax code is built
Most codes are a number followed by a letter. The number is your tax-free pay for the year with the last digit dropped — so 1257L means £12,570 of tax-free Personal Allowance. HMRC starts from the standard allowance and takes off anything you owe tax on another way (a company car, taxable benefits, untaxed interest, or tax owed from a past year), then replaces the final digit with a letter that explains your situation.
- L — you get the standard tax-free Personal Allowance (the normal code)
- M / N — Marriage Allowance: you've received (M) or given (N) a 10% transfer of allowance
- T — your allowance needs extra HMRC calculations (often income near £100,000)
- 0T — no tax-free pay left, but tax still steps up through the 20/40/45% bands
- BR / D0 / D1 — the whole of this income is taxed at 20% / 40% / 45%, with no allowance (usually a second job or pension)
- K — you have untaxed income or deductions bigger than your allowance, so the code adds to your taxable pay instead of giving tax-free pay
- NT — no tax is taken from this income at all
An S at the front means Scottish rates and a C means Welsh rates. A W1, M1, X or NONCUM on the end is an emergency code — read on for what that means.
Emergency tax codes — and why you might be overpaying
If your code ends in W1, M1 or X, you're on an emergency code. It taxes each pay packet on its own, as if you earned that amount every week or month, instead of looking at your total pay so far. You usually land on one after starting a new job before your new employer has your P45. A pure BR or 0T code on what is actually your only job does the same damage — it hands none of your tax-free allowance to that job, so you're taxed on pounds that should be free.
The good news: it usually sorts itself out — and you can reclaim
Give your new employer the P45 from your last job (or fill in the HMRC "new starter" details) and your code normally corrects within a pay run or two. Any tax you overpaid on an emergency code comes back — either automatically in a later payslip once the right code kicks in, or as a refund after HMRC reconciles the year. Check your code any time in the free HMRC Check your Income Tax service.
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Common questions
What does the tax code 1257L mean?
1257L is the standard tax code for most people with one job or pension in 2026/27. The number 1257 means you get £12,570 of tax-free Personal Allowance for the year (the number times ten), and the letter L means you're entitled to the standard allowance. Anything you earn above £12,570 is taxed at 20%, then 40% above £50,270 and 45% above £125,140.
Why is my tax code BR or 0T, and am I paying too much tax?
A BR code taxes all of that income at the basic rate (20%) with no tax-free allowance; a 0T code gives no allowance either but steps up through the 20/40/45% bands. Both are normal on a second job or pension, where your allowance is used against your main job. But if BR or 0T is on your only job, you're being taxed on pay that should be tax-free — often because a new employer didn't have your details. Give them your P45 or update your details with HMRC, and any overpayment is refunded.
What is an emergency tax code (W1, M1 or X)?
A code ending in W1, M1, X or NONCUM is an emergency code. It works out your tax on each week's or month's pay in isolation, rather than on your income for the year so far, so you can pay the wrong amount. It's usually temporary after starting a new job. Once HMRC has your full details — from your P45 or your previous employer — you're moved onto a normal cumulative code and any overpaid tax is repaid.
What does a K tax code mean?
A K code means you have untaxed income or deductions — such as a company car, taxable benefits, the State Pension, or tax owed from an earlier year — that add up to more than your Personal Allowance. Instead of giving you tax-free pay, a K code adds the excess to your taxable pay. To protect you, HMRC can never take more than half of your pre-tax pay from a source using a K code.
How do I change my tax code if it's wrong?
You can't change it directly with your employer — HMRC issues it. Use the free HMRC "Check your Income Tax" service online or the HMRC app to see how your code was worked out and tell them about anything that's changed (a company benefit that ended, a second job that stopped). HMRC then sends a corrected code to you and your employer, and your next payslip picks it up. Overpaid tax is refunded through your pay or after the tax year ends.
Know your whole tax position, not just the code
Your tax code is one line on a payslip. The paid Self Assessment Tax Estimator models your whole year — salary plus any freelancing or side income, pension and student loan — so you can see your real tax bill, spot when a wrong code has left you owing or owed, and plan around it to the penny.
- Self Assessment Tax Estimator 2026/27 — your whole bill, salary plus self-employment, with the monthly set-aside and payment-on-account dates worked out for you.
- Freelance Day-Rate & Profit Calculator — work backwards from the take-home you need.
- Rental Property ROI & Yield Calculator — for anyone with a buy-to-let alongside.
- Invoice Tracker & Log — paid, outstanding and overdue, automatically.
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