Guide to Employee Tax Codes
Paying the correct amount of tax every year is only possible if you have implemented the correct tax code.
If you’re a business owner, self-employed professional or an employee in the UK, the tax code on your payslip may be something that you rarely give notice to, or often gloss over. However, it’s worth understanding how tax codes work, what they mean, and how to spot and resolve common issues on payslips.
Here’s an up-to-date, straightforward guide to the most common UK tax codes you’ll see, and how to interpret them. This guidance from the tax advisors at Hamlyns affects both employers and employees, as it’s a surprisingly common circumstance that a person’s tax code is incorrect.
What Is a Tax Code?
A tax code tells your employer or pension provider how much income tax to deduct from your salary.
A tax code consists of both numbers and letters, each signifying a different allowance or circumstance.
If your tax code is incorrect, you might either pay too much tax or not enough tax, so it’s important to check your payslip regularly and ensure your corresponding tax code is correct and up-to-date.
The Standard Tax Code for 2025–26
For most employees in England, Wales, and Northern Ireland, the tax code for 2025–26 is 1257L. This indicates that you’re entitled to the full personal allowance (i.e., the amount you can earn before paying tax, which equates to £12,570 as of this tax year).
If you have one job and no untaxed income, unpaid tax, or taxable benefits, you’ll usually see this code on your payslip.
Interpreting this tax code is straightforward:
The number 1257, when multiplied by 10, shows your annual tax-free allowance (£12,570). The ‘L’ means you’re eligible for the standard allowance.
Common Tax Codes Explained
Here are other codes you might spot, and what they mean:
| Tax Code | What it Means |
| 1257L | Standard code – full Personal Allowance |
| BR | Basic Rate – all income taxed at 20% (used for second jobs/pensions) |
| 0T | No tax-free Personal Allowance – often used if your Personal Allowance is used up, or your circumstances aren’t known |
| D0 | All income taxed at 40% (higher rate, usually for additional earnings/jobs) |
| D1 | All income taxed at 45% (additional rate, for high amounts) |
| K*** | You have tax owing from a previous year, or have taxable benefits that exceed your Personal Allowance (the number that follows the K shows how much must be added to your earnings before tax is calculated) |
| NT | No tax deducted |
| S, C, W Prefixes | Indicates that Scottish (S), Welsh (C), or other regional rates apply. |
| M or N | Marriage Allowance transfer (M for receiver, N for transferor) |
Emergency Tax Codes
If you start a new job and your employer doesn’t have the right details, you may be placed on an emergency code.
For example, you may see the ‘1275L’ followed by a letter and a number, such as W1, M1 or X. This is what they refer to:
1257L W1, 1257L M1, or 1257L X
- W1: Week 1 basis (tax recalculated weekly)
- M1: Month 1 basis (tax recalculated monthly)
- X: Used with non-standard pay periods
Emergency codes mean you get the standard allowance, but your tax isn’t calculated on a cumulative basis, which can lead to over- or underpayment. Once HMRC has the correct details, your code will be updated automatically.
What To Do If Your Tax Code Is Wrong
If your tax code doesn’t match your circumstances, tell your employer and contact HMRC as soon as you can. You might need to provide your P45 or P60 details, or information about multiple jobs you hold or taxable benefits you may be entitled to. An incorrect code can result in paying too much or too little tax, so resolving issues promptly and transparently is key.
Understanding your tax code helps you keep more of your hard-earned money and avoid unexpected tax bills. For tailored advice or if you believe your situation is more complex, the specialist team at Hamlyns is ready to help. Contact Hamlyns’ professional advisors for tax planning, payroll, and all your accountancy needs.
