Tax Code Checker
Enter your PAYE tax code to see exactly what it means, your implied Personal Allowance, and whether it's flagging anything worth double-checking with HMRC — an MSE classic that catches thousands of overpayers every year.
Estimate only. This is an estimate for information only, not tax advice. Always check your actual tax code and any overpayment with HMRC or a qualified adviser.
L — standard code
You get the standard tax-free Personal Allowance. This is the most common code and normally means nothing more to check, unless the number itself looks lower than you'd expect.
This matches the standard allowance for 2026/27.
No red flags — this looks like a normal, correctly structured code.
- Check after every job change, pay rise, or new company benefit — tax codes often lag behind and can take a while to catch up.
- Company benefits (car, medical insurance, gym membership) usually shrink your code via a K code or a reduced number — check your P11D matches what HMRC has on file.
- You can reclaim overpaid tax going back 4 tax years — don't assume a mistake from a few years ago is too late to fix.
- Your Personal Tax Account (gov.uk) shows your current code and lets you tell HMRC about changes directly, without waiting for a letter.
How to read a UK tax code
Most tax codes are a number followed by a letter — the number, multiplied by 10, is your tax-free Personal Allowance for that job (1257L means £12,570). The letter explains why: L is standard, M and N relate to Marriage Allowance, and T flags a code HMRC wants to review manually. Some codes skip the number entirely — BR, D0 and D1 tax every pound at a single flat rate with no tax-free amount, which is normal for a second job but a red flag if it's your only income. A K prefix works in reverse, adding untaxed income to your pay instead of subtracting an allowance from it. Finally, W1, M1 or X on the end mark an emergency, non-cumulative code that taxes each payslip in isolation rather than against your running total for the year.