Understanding your employees' tax codes

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1. Overview

You put an employee’s tax code into your payroll software to work out how much tax to deduct from their pay throughout the year.

This guide is also available in Welsh (Cymraeg).

There’s a separate guide on tax codes if you’re an employee.

What you need to do

When you take on a new employee, you normally work out their tax code by using their P45. The code will usually be made up of several numbers and one letter, such as 1257L.

You usually need to update your employee’s tax code at the start of a new tax year. If the tax code changes during the year, HM Revenue and Customs (HMRC) will email you - you should update your payroll records as soon as possible.

Tax code 1257L

The most common tax code for tax year 2024 to 2025 is 1257L. It’s used for most people with one job and no untaxed income, unpaid tax or taxable benefits (for example a company car).

1257L is an emergency tax code only if followed by ‘W1’, ‘M1’ or ‘X’. Emergency codes can be used if a new employee does not have a P45.

2. What the numbers mean

The numbers in an employee’s tax code show how much tax-free income they get in that tax year.

You usually multiply the number in the tax code by 10 to get the total amount of income they can earn before being taxed.

For example, an employee with the tax code 1257L can earn £12,570 before being taxed. If they earn £27,000 per year, their taxable income is £14,430.

The process is different if the employee has the letter ‘K’ in their tax code.

3. What the letters mean

Letters in an employee’s tax code refer to their situation and how it affects their Personal Allowance.

Code How tax is deducted When this code is usually used
0T From all income - there is no Personal Allowance When an employee has not given you a P45 or enough details to work out their tax code, or when their Personal Allowance has been used up
BR From all income at the basic rate For a second job or pension
C From income in the Welsh tax bands For an employee whose main home is in Wales
C0T From all income - there is no Personal Allowance When an employee whose main home is in Wales has not given you a P45 or enough details to work out their tax code, or when their Personal Allowance has been used up
CBR From all income at the basic rate in Wales For a second job or pension
CD0 From all income at the higher rate in Wales For a second job or pension
CD1 From all income at the additional rate in Wales For a second job or pension
D0 From all income at the higher rate For a second job or pension
D1 From all income at the additional rate For a second job or pension
L At basic, higher and additional rates depending on the amount of taxable income For an employee entitled to the standard tax-free Personal Allowance
M At basic, higher and additional rates depending on the amount of taxable income For an employee whose spouse or civil partner has transferred some of their Personal Allowance
N At basic, higher and additional rates depending on the amount of taxable income For an employee who has transferred some of their Personal Allowance to their spouse or civil partner
NT No tax is deducted Very specific cases, for example musicians who are regarded as self-employed and not subject to PAYE
S From income in the Scottish tax bands For an employee whose main home is in Scotland
S0T From all income - there is no Personal Allowance When an employee whose main home is in Scotland has not given you a P45 or enough details to work out their tax code, or when their Personal Allowance has been used up
SBR From all income at the basic rate in Scotland For a second job or pension
SD0 From all income at the intermediate rate in Scotland For a second job or pension
SD1 From all income at the higher rate in Scotland For a second job or pension
SD2 From all income at the advanced rate in Scotland For a second job or pension
SD3 From all income at the top rate in Scotland For a second job or pension
T At basic, higher and additional rates depending on the amount of taxable income When HMRC needs to review some items with the employee

If your employee’s tax code has ‘W1’ or ‘M1’ at the end

W1 (week 1) and M1 (month 1) are emergency tax codes and appear at the end of an employee’s tax code, for example ‘577L W1’ or ‘577L M1’. Calculate your employee’s tax only on what they are paid in the current pay period, not the whole year.

Tax codes with the letter ‘K’

The letter K is used in an employee’s tax code when deductions due for company benefits, state pension or tax owed from previous years are greater than their Personal Allowance.

Multiply the number in their tax code by 10 to show how much should be added to their taxable income before deductions are calculated.

Example An employee with tax code K475 and a salary of £27,000 has taxable income of £31,750 (£27,000 plus £4,750).

The tax deduction for each pay period cannot be more than half an employee’s pre-tax pay or pension.

4. Changes during the tax year

Usually someone’s tax code changes if their tax-free income (Personal Allowance) goes up or down. For example if they start or stop receiving a taxable benefit like a company car.

  1. HM Revenue and Customs (HMRC) will send you an email alert if one of your employees’ tax codes changes.

  2. Access the new tax code in PAYE Online (in ‘tax code notices’), the PAYE Desktop Viewer application, or in your payroll software (if it has this feature). Check if your employee’s previous pay and tax are included with the new tax code. If they are, note these figures.

  3. As soon as possible, and before you next pay your employee, update their payroll record with their new tax code. Add their previous pay and tax, if you received these figures with the new tax code.

A tax code notice is sometimes called a P6 form.

If you receive an employee’s new tax code too late to use in the tax year, you should use it in the new tax year.

5. Updating for the new tax year

HM Revenue and Customs (HMRC) will tell you between January and March about any new tax codes to use for employees in the new tax year. This starts on 6 April.

If an employee’s tax code is not changing, HMRC will not contact you and you should carry forward the employee’s tax code to the new tax year.

If your employee’s tax code ends with ‘M1’ or ‘W1’ (‘month 1’ or ‘week 1’), do not carry this part of the code into the new tax year.