🔢 What does my UK tax code mean?

Your tax code shows how much of your income is tax-free before deductions begin. For example, the common code "1257L" means you get a £12,570 personal allowance, while "BR" means all your income from that job is taxed at 20%.

🤔 Why has my tax code changed this year?

HMRC can change your tax code if your income, benefits, or employment situation changes. You might get a new code after starting a second job, receiving benefits, or claiming a tax refund.

Tax Codes UK: What They Mean and How They Affect Your Pay

If you're having problems with your pay or your taxes, your tax code could be to blame. Tax codes tell the HMRC how to tax employees. Here's everything you need to know about them.

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What Is a Tax Code?

Your tax code is a way for your employer or pension provider to know how much Income Tax they should deduct before they pay you. In the UK, your tax code is a combination of numbers and letters (for example, 1257L). This code is set by HM Revenue & Customs (HMRC). It is based on your Personal Allowance and adjustments (benefits in kind, under/overpayments from earlier years, multiple jobs, etc.). Your tax code can be found on your payslip, P45 (when you leave a job), P60 (year-end summary), coding notices from HMRC, and inside your Personal Tax Account.

Two piles of UK coinage. — Your tax code is an indication of what tax you should be paying. | Photo by Sarah Agnew

Generally, the numbers represent your tax-free amount multiplied by ten (E.g., the aforementioned 1257L code means the allowance is £12,570). The letter indicates how HMRC should apply UK/Scottish/Welsh rates or special situations like Marriage Allowance, emergency codes, or 'K' codes where deductions exceed the allowance.

How Your Tax Code Works

- Numbers = your tax-free amount (÷10).
Example: 1257 ⇒ £12,570 Personal Allowance.

- Letters = how HMRC should apply tax.

L standard allowance · M/N Marriage Allowance · K deductions exceed allowance · S Scottish taxpayer · C Welsh taxpayer.

-Emergency suffixes: W1/M1/X mean temporary emergency code until HMRC updates your details.

How a Tax Code Affects Your Income

Your tax code dictates how much tax is taken off each payday. If your code is correct, then PAYE should collect the right tax across the year without you needing to do anything. However, if your tax code is wrong (on BR at a primary job or on an emergency code when you shouldn't be), you could end up overpaying or underpaying.

When you overpay or underpay, you'll need an adjustment or refund later, and the codes are generally designed to minimise the likelihood of this happening. You can always check and update details that affect your tax code by using your Personal Tax Account.

An accountant with a client. — Speak to professionals if you have issues with your tax or tax codes. | Photo by Scott Graham

Common UK Tax Codes and What They Mean

There's really no need to go through every single tax code, but it's essential to know the most common ones. What you're really looking for is that you're in the right area. Here are the codes you'll most often see on payslips:

1257L: the most common code for 2025/26. It means you receive the standard £12,570 Personal Allowance and have no other adjustments. (It’s only an emergency code if followed by W1 / M1 / X)

BR: all income from this job/pension is taxed at the basic rate (commonly used for a second job or additional pension).

D0 / D1:your income from this job/pension is taxed at higher or additional rates (often used for second jobs/pensions when your allowance is used elsewhere).1

0T: no Personal Allowance is being used on this income (e.g., new job without P45/details or your allowance has been fully used).

NT: no tax is being deducted from this income (rare; specific circumstances).

S-prefix codes (e.g., S1257L, SBR): you’re a Scottish taxpayer, so Scottish income-tax rates/bands apply.

C-prefix codes (e.g., CBR, C0T): you’re a Welsh taxpayer, so Welsh rates apply (usually aligned with rUK bands but set by the Welsh Government).

Code	What It Means	Typical Use Case
1257L	Standard Personal Allowance (£12,570).	Main job/pension with no adjustments.
1257L W1/M1/X	Emergency code (weekly/monthly basis).	New job; HMRC awaiting details.
BR	All income taxed at basic rate (20%).	Second job or extra pension where allowance used elsewhere.
D0	All income taxed at higher rate.	Additional job/pension for higher-rate payer.
D1	All income taxed at additional rate.	Additional job/pension for additional-rate payer.
0T	No Personal Allowance applied.	No P45/new starter details; allowance fully used.
NT	No tax deducted.	Specific, rare circumstances.
S1257L / SBR / SD0 etc.	Scottish taxpayer variants.	Resident in Scotland for tax purposes.
C1257L / CBR / CD0 etc.	Welsh taxpayer variants.	Resident in Wales for tax purposes.
K500 (example)	Deductions exceed allowance (code collects extra).	Benefits in kind/underpaid tax coded in.

Emergency Tax Codes Explained

The codes that end with W1, M1, or X are temporary emergency codes (e.g., 1257L W1/M1/X). You'll typically get an emergency tax code when you start a new job. Your employer doesn't have your full details, you've moved from self-employment to employment, or you've begun receiving certain benefits or the State Pension. HMRC will usually correct emergency codes when your information is updated.

On an Emergency Code?

Don't panic — W1/M1/X codes are temporary.
- Give your employer your P45 (or complete the starter checklist if you don’t have one).
- Check your Personal Tax Account and confirm your job/pension details.
- HMRC will update your code; any overpaid tax is usually refunded automatically.

An accountant with a calculator. — Don't panic about an emergency tax code, it's easily and relatively quickly changed. | Photo by charlesdeluvio

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How To Check Your Tax Code

It isn't too tricky to check your tax code, and if something seems off about your pay, it could be the problem. There are a few ways to check it. They're all relatively easy:

Look at your payslip (it appears near your name/NI number).

Check HMRC’s Personal Tax Account. It shows your current code, what HMRC believes your income is, and any benefits or adjustments included.

If you’ve just left a job or started a new one, check your P45; at tax year end, check your P60.

If HMRC changes your code, they usually send a coding notice, and the change appears in your account.

If you find something's off about your tax code, contact HMRC. You can get codes re-allocated. Generally, these issues only occur when changing or starting new jobs. However, there are a few other rarer reasons.

Why Has My Tax Code Changed?

When HMRC gets new information, it'll likely change your tax code. This can occur throughout the year as and when information is updated. Here are some of the most common reasons for the change:

New job or second job: HMRC may temporarily move your allowance; a second job is often put on BR until details are confirmed.

Benefits in kind (e.g., company car, medical insurance): the estimated value of benefits reduces your tax-free amount, changing your code.

Under/overpayments from prior years: HMRC can collect small underpayments through your current code (reducing the number), or repay overpayments directly to you (sometimes via P800 calculations).

Starting State Pension: like other taxable income, it can be coded in and reduce the allowance on a job.1

Becoming a Scottish or Welsh taxpayer: if you move or HMRC updates residency for tax banding, your prefix can change to S or C.

How To Correct a Wrong Tax Code

Incorrect tax codes can be a pain. However, you can change them quite easily. Here's how:

Check details in your Personal Tax Account: employer(s)/pension(s) listed, estimated pay, benefits, and allowances.

Update income estimates or remove old employers where appropriate.

Ask HMRC to split your allowance if you have multiple jobs and want part of the allowance on each (rather than BR on the second).

Provide missing documents to your employer (P45 when you start; correct starter checklist if no P45).

Follow up: once updated, the new code is sent to your employer/pension provider; your next payslip should reflect the change.

If you've overpaid because of a wrong code, HMRC usually refunds you automatically either through payroll, directly after a P800, or via your online account. If you've underpaid, HMRC may collect it through your code across the year or through a single payment.

An accountant working. — Get in touch with HMRC to rectify tax codes. | Photo by JESHOOTS.COM

How To Check or Change Your Tax Code

Check your code on your latest payslip and inside your Personal Tax Account.

Confirm employers/pensions listed and your estimated pay for this year.

Update benefits in kind (car, medical), and remove old employers if shown.

Ask HMRC to split your allowance if you have two jobs (so the second isn’t on BR).

Provide your P45 (or starter checklist) to new employers.

Re-check the following payday to confirm the new code has been applied.

Refunds/underpayments: HMRC will usually refund through payroll or settle via P800/online; small underpayments can be collected through your code.

How To Contact HMRC About Your Tax Code

Tax-code issues can often be handled online. You can also call HMRC if you have multiple changes or complex benefits. If you plan on doing this, we recommend that you have ready:

NI number and Personal Tax Account login

Employer/pension provider details

Recent payslips and any coding notices (HMRC letters)

P45/P60, if relevant

Remember that HMRC will never ask for your bank/card details by SMS or email to pay your tax. If you receive any suspicious emails or messages claiming to be from HMRC, never click the links; instead, connect directly through the HMRC website. You can also forward suspicious texts to 60599.

Final Tips for Understanding Tax Codes

In short, tax codes aren't as scary as they sound. Understanding what code you should be on and roughly what the codes mean will help a lot. Here's our key advice on UK tax codes:

One Personal Allowance per tax year. Use it on your main job/pension. Additional jobs are often on BR/D0/D1 unless HMRC splits the allowance.

Scottish/Welsh taxpayers use S- or C- prefix codes so HMRC applies the right rates. Check that your address is correct with HMRC.

Emergency codes (W1/M1/X) are temporary. Supply missing details to your employer and monitor your Personal Tax Account to ensure HMRC updates your code.

If your take-home pay suddenly changes, check your code first — a new benefit, a second job, or a correction may have triggered a change. Use the online account to see the reason and fix it quickly.

Keep an eye out for P800 notices after year-end. They reconcile your PAYE position and may result in a refund or a small balance to pay. (You'll see these in your online account too.)