Tax Codes Explained: What Yours Means for Your Take-Home Pay

Your tax code is a short mix of numbers and a letter that tells your employer or pension provider how much Income Tax to take from your pay. Get it right and your take-home pay looks after itself. Get it wrong and you can end up paying too much, or too little, without ever realising why.

In this insight we explain what a tax code actually is, how the number and the letters work, where to find yours, and how it shapes the money that lands in your account each payday. You can also drop your own code into the decoder below to see what it means in plain English.

🔎 Tax code decoder · live

Enter your tax code (from your payslip or P45/P60)

Tax-free pay this year£12,570

You get £12,570 of tax-free pay this year — the standard tax-free Personal Allowance.

Explains the code only; it doesn’t calculate your tax — for that, use our income tax calculator. If you think your code is wrong, contact HMRC. Codes and the 2025/26 standard code (1257L) can change; always check gov.uk.

At a glance

What it is: A code telling your employer how much tax-free pay you get
The number: Your tax-free amount for the year, divided by 10
Standard code: 1257L for 2025/26 (£12,570 tax-free)
Where to find it: Payslip, P45, P60 or your HMRC online account

Key Takeaways

A tax code tells your employer or pension provider how much of your income is tax-free, so it controls how much tax is deducted before you are paid.
The number is your annual tax-free amount with the last digit removed, so the common 1257L code means £12,570 of tax-free pay for 2025/26.
The letters carry extra meaning, from the standard L to BR (all basic rate), D0 (all higher rate), 0T (no allowance) and K (extra taxable income).
Your code can be wrong, so it is worth checking it against your payslip and HMRC account, especially after a job change or a new benefit at work.

What Is a Tax Code?

A tax code is the instruction HMRC gives your employer or pension provider so they know how much Income Tax to deduct from each payment. It works through the PAYE (Pay As You Earn) system, which collects tax gradually across the year rather than in one lump sum.

Most people in England, Wales and Northern Ireland have a Personal Allowance, an amount you can earn each year before Income Tax starts. For 2025/26 the standard Personal Allowance is £12,570. Your tax code turns that allowance into a running figure your employer can apply to every payday, spreading your tax-free pay evenly across the year.

If you want to see how a code translates into actual pounds in your pocket, our income tax calculator does the sums for you based on your salary.

How the Number Works

The number in your tax code is simply your tax-free amount for the year with the final digit removed. So a Personal Allowance of £12,570 becomes 1257, and a tax-free amount of £11,000 would become 1100.

To reverse it, multiply the number by 10. A code of 1257L means roughly £12,570 of tax-free pay; a code of 1000L would mean about £10,000. Anything you earn above that tax-free figure is taxed at the normal rates, currently 20% basic rate, 40% higher rate and 45% additional rate in England, Wales and Northern Ireland. Scotland has its own set of bands.

The number can be lower than the standard allowance if you owe tax from a previous year or receive taxable benefits at work, and it can be higher if you have extra tax-free allowances. That is why two people on the same salary can have different codes.

What the Letters Mean

The letter, or letters, add context about your situation. The most common ones are:

L - you get the standard tax-free Personal Allowance.
M - you receive Marriage Allowance from your partner.
N - you have given Marriage Allowance to your partner.
T - your code includes other calculations HMRC needs to review.
BR - all income from this job or pension is taxed at the basic rate (20%).
D0 - all income is taxed at the higher rate (40%).
D1 - all income is taxed at the additional rate (45%).
0T - you have no tax-free allowance left for this income.
NT - no tax is taken at all.
K - you have income or benefits that are not being taxed another way, so tax is added rather than allowance given.

You may also see a letter at the front. An S prefix means Scottish rates apply, and a C prefix means Welsh rates apply. If you take a second job, codes such as BR or 0T often show up there, which we cover in our guide to the tax code for a second job.

Emergency and Non-Cumulative Codes

Sometimes you will see W1, M1 or X at the end of your code. These are emergency, or non-cumulative, codes. They tell your employer to work out tax on that pay period alone, rather than looking at what you have earned so far this year.

They often appear when you start a new job without a P45, and they can lead to over or underpayments until HMRC has your full details. Our guide to the emergency tax code explains how to get back onto the right code and reclaim anything you have overpaid. If your code has recently changed for any reason, why has my tax code changed walks through the usual causes.

Where to Find Your Tax Code

You can find your current tax code in several places:

Your payslip, usually near your National Insurance number.
Your P45 when you leave a job.
Your P60 at the end of the tax year.
A PAYE coding notice (form P2) from HMRC.
Your personal tax account on GOV.UK, which is the quickest way to see your live code and tell HMRC if something looks wrong.

If you are also weighing up how far your pay stretches, our look at what counts as a good salary in the UK puts take-home pay into context, and you can explore more tools on our calculators page.

Frequently asked questions

How do I know if my tax code is correct?

Compare the code on your payslip with your circumstances. If you have one main job, no taxable work benefits and no tax owed from before, you would usually expect the standard code for the year. If the number looks unusually low, or you see BR, D0, 0T or K unexpectedly, check your HMRC online account and contact HMRC if it seems wrong.

What is the standard tax code for most employees?

For the 2025/26 tax year the standard code is 1257L, reflecting the £12,570 Personal Allowance. Most people with a single job and no complicating factors have this code. Our guide to what tax code 1257L means explains it in full.

Does my tax code change every year?

It can. HMRC reviews codes ahead of each tax year and may adjust yours for changes to allowances, benefits at work, or tax owed from a previous year. Even if the headline allowance stays the same, your personal code can move, so it is worth a quick check each April.

Can the wrong tax code mean I pay too much tax?

Yes. An incorrect code, such as an emergency code that lingers or a BR code applied to your only job, can lead to overpaying. If HMRC has too little information, it may err on the side of taking more. The good news is that overpaid PAYE tax is usually refunded once your code is corrected.

General information only, not financial advice. If you think your tax code is wrong, contact HMRC.