What a tax code does
HMRC issues your tax code to your employer or pension provider, and it tells them how much of your pay to treat as tax-free through PAYE. See our guide to how PAYE works for the wider system this fits into.
How it's structured
Most tax codes are a number followed by a letter. The number relates to your tax-free allowance for the year. HMRC starts from the standard Personal Allowance (£12,570.00 for 2026/27) and adjusts it for things like untaxed income or company benefits. The letter reflects your situation and how it affects your Personal Allowance: for example, L means you're getting the standard Personal Allowance, and other letters apply to circumstances such as the Marriage Allowance, having your Personal Allowance already used up elsewhere, or Scottish or Welsh rates.
Emergency tax codes
An emergency code is used when your employer doesn't yet have your full income and tax details, for example when you start a new job without a P45, or start getting a new company benefit or the State Pension. It usually ends in W1, M1, or X, or shows as "non-cumulative". This means each pay period is taxed on its own, as if you were paid that amount every period of the year, which can be inaccurate until HMRC has your full details.
If you think your code is wrong
WageOra can't tell you what your own tax code should be. That depends on details HMRC holds about your specific circumstances. If you've started a new job, giving your new employer your P45 usually lets HMRC correct your code automatically. Otherwise, you can check or query your tax code directly with HMRC.
See an estimate, not a personalised code
The Salary Calculator estimates take-home pay assuming the standard Personal Allowance applies, for the 2026/27 tax year. It doesn't read or calculate your actual tax code. See How WageOra Works for the assumptions it uses.