Your tax code sets your tax-free allowance. Enter your salary and code — 1257L, BR, D0 or a K code — to see your allowance, Income Tax, National Insurance and take-home pay.
Salary · tax code · 2026/27
Your tax code tells your employer how much tax-free pay you get before Income Tax starts. The most common code, 1257L, means a £12,570 allowance (multiply the number by 10). But letters and special codes change the picture entirely — and a wrong code is one of the most common reasons people overpay or underpay tax.
| Tax code | What it means |
|---|---|
| 1257L | Standard £12,570 tax-free allowance |
| BR | All income taxed at basic rate (20%) |
| D0 / D1 | All income taxed at 40% / 45% |
| K codes | Allowance is negative — added to taxable pay |
| NT | No tax deducted |
For a normal code, the number × 10 is your tax-free allowance, and the letter shows your situation — L for the standard allowance, M/N for transferred Marriage Allowance, T for codes needing review. A K code works in reverse: it means deductions (like a company car benefit) exceed your allowance, so the figure is added to your taxable pay.
An incorrect code is surprisingly common after changing jobs, getting a benefit like a company car, or starting a pension. If your take-home looks off, check the allowance this calculator derives against your payslip. For the standard full breakdown including pension and student loan, use the gross to net calculator.
1257L gives the standard £12,570 tax-free allowance (1257 × 10), with the L confirming the basic Personal Allowance — the most common code.
BR taxes all pay at 20%, D0 at 40% and D1 at 45% with no allowance — usually on a second job or pension where your allowance is used up.
A K code means your taxable benefits exceed your allowance, so the figure is added to your taxable pay rather than deducted — you're taxed on more than your salary.
Benefits, a second job, transferred Marriage Allowance, or collecting underpaid tax can all change your code from 1257L — check it against your payslip if unsure.
