What is a UK tax code?
Your UK tax code tells your employer how much Income Tax to deduct from your salary before you’re paid. It’s issued by HMRC and applied through the PAYE system.
The code reflects your personal allowance, any adjustments, and whether your income should be taxed at a flat rate.
Common UK tax codes and what they mean
| Tax Code | Meaning |
|---|---|
| 1257L | Standard tax code with the full personal allowance. |
| BR | All income taxed at the basic rate (20%). |
| 0T | No personal allowance applied. |
| K | You owe tax from a previous year or have taxable benefits. |
| Emergency | Temporary code used when HMRC lacks information. |
Why does my tax code change?
- Starting or changing jobs
- Receiving benefits in kind (company car, health insurance)
- Underpaying or overpaying tax previously
- Incorrect or missing information at HMRC
What if my tax code is wrong?
If your tax code looks wrong, don’t panic. This is common and usually easy to fix.
- Check your latest payslip
- Log in to your HMRC Personal Tax Account
- Contact HMRC if needed
Employers cannot change tax codes themselves — they must follow HMRC instructions.
How your tax code affects take-home pay
Different tax codes can significantly change how much tax is deducted from your salary.
Calculate your take-home pay