September 4, 2025

The letters in your tax code indicate whether you are entitled to the annual tax-free personal allowance. These codes are updated each year and help employers calculate how much tax should be deducted from your salary.

For the current tax year, the basic personal allowance is £12,570. The tax code corresponding to this amount is 1257L, which is the most common tax code used for those with a single job, no untaxed income, and no unpaid tax or taxable benefits (such as a company car).

HMRC updates your tax code when your circumstances change, and your taxable income is affected. Some common reasons why your tax code may change include:

It is important to check your tax code is correct. If you have any questions, we would be happy to help.