British Tax Codes 2026/27: What 1257L, BR, T & 0T Mean

By Eternity Accountants Editorial Team · Reviewed by Shamayun Chowdhury, Senior Accountant · Published: 7 November 2026 · Last reviewed: November 2026 · Applies to the 2026/27 tax year

A tax code is only a few characters long, yet it decides how much Income Tax leaves every payslip. A wrong code can mean months of overpaid tax, or a bill at year end. HMRC issues one code for each job or pension you have, so people with two incomes often hold two different codes.

This guide decodes British tax codes in plain English. It covers what the numbers and letters mean, a full list of codes, emergency and K codes, and how to check and fix yours, with worked examples at 2026/27 rates.

What Are British Tax Codes?

British tax codes are the instructions HMRC sends to employers and pension providers under PAYE (Pay As You Earn). As GOV.UK’s tax codes guidance explains, your payer uses the code to work out how much Income Tax to take from your pay or pension. You never choose your own code. HMRC sets it from the information it holds about you.

The code does two jobs. First, it shows how much of your income from that source is tax-free. Second, it tells payroll which rates and bands to apply, including Scottish or Welsh rates where they apply.

Why do people have different British tax codes?

Your code reflects your whole tax position, not just your salary. Company benefits such as a car or private medical cover, untaxed income, Marriage Allowance, tax owed from an earlier year and a second job can all move it away from the standard figure.

When do tax codes change?

HMRC normally issues fresh British tax codes for the start of each tax year on 6 April. It can also change your code mid-year when it learns about a new job, a pay rise, a new benefit or the State Pension. You may get a Tax Code Notice by post or online.

How to Read a Tax Code: Numbers and Letters

Most British tax codes combine a number and a letter. Read them separately and the code quickly makes sense.

What the numbers mean

The number is your tax-free amount from that job or pension with the last digit removed. HMRC starts with the standard Personal Allowance of £12,570, takes off anything that reduces it, adds anything that increases it, and then drops the final digit. GOV.UK’s own example is a tax-free amount of £11,000, which becomes the code 1100L.

• Things that reduce the number: company benefits, untaxed income such as some interest or casual earnings, tax owed from a previous year, and the High Income Child Benefit Charge.
• Things that increase the number: receiving Marriage Allowance, or allowable job expenses such as professional subscriptions and uniform costs.

What the letters mean

The letter describes your situation. L is the standard letter. M and N relate to Marriage Allowance, T means HMRC needs to review something, and K means deductions exceed your allowance. A letter at the front, S or C, shows that Scottish or Welsh rates apply.

List of British Tax Codes and What They Mean

The table below draws on GOV.UK’s guide to what your tax code means and HMRC’s employer guidance. It covers the British tax codes you are most likely to see on a payslip or HMRC letter.

Tax code BR explained

BR stands for basic rate. Every pound from that job or pension is taxed at 20%, with no tax-free amount. It is normal on a second job when your Personal Allowance is already used in your main job. If your total pay from all sources is below £12,570, a BR code may mean you are overpaying.

Tax code T explained

A T code works like an L code for the rates applied, but it tells payroll that HMRC wants to review something with you. That could be a reduced allowance on income over £100,000 or another item it needs to confirm. You are not in trouble if you see a T, but check the figures.

Tax code 0T explained

0T gives you no tax-free pay at all. HMRC uses it when your Personal Allowance has been used up, or when a new employer does not have the details it needs. Income of more than £125,140 removes the allowance entirely, so higher earners may legitimately hold 0T.

Emergency Tax Codes: W1, M1 and X

Emergency British tax codes have W1, M1 or X at the end, such as 1257L W1 or 1257L M1. According to GOV.UK’s emergency tax codes page, W1 is for weekly pay, M1 for monthly pay, and X for varying pay dates. Some payslips show NONCUM instead.

Under an emergency code, tax is worked out only on the pay for that week or month, as if you earn the same amount every period. Allowance you did not use earlier in the year is ignored, so you can pay the wrong amount.

How to get off an emergency code

1. Give your new employer your P45 from your last job. Ask your old employer for it if you do not have one.
2. Wait for HMRC to update your code, which can take up to 35 days from your start date.
3. If more than 35 days have passed and the code is still wrong, update your details through HMRC’s online service.

If you overpaid tax while on an emergency code, the extra is normally refunded through your pay once the code is corrected, or you can claim it back from HMRC.

K Codes Explained

Among British tax codes, K is the one that works in reverse. It means the deductions in your code are bigger than your Personal Allowance. That can happen with a valuable company car, a State Pension paid in full without tax, or tax owed from an earlier year. Instead of giving you tax-free pay, a K code adds extra taxable income.

To work out the effect, multiply the number after the K by 10 and add it to your pay. HMRC’s employer guidance gives the example of K475 on a £27,000 salary: £4,750 is added, so tax is worked out on £31,750.

The 50% safeguard

The tax taken under a K code cannot be more than half of your pre-tax pay or pension in each pay period. Any tax that cannot be collected because of this limit is carried forward, so you may still owe it later. The rules sit in HMRC’s PAYE Manual (PAYE11095).

British Tax Codes in Scotland and Wales

British tax codes start with S if you live in Scotland and C if you live in Wales. The prefix depends on where your main home is, not where your employer is based. A Glasgow resident working for a London company still gets an S code.

Scotland has more bands, so it has extra flat-rate codes. SD0 taxes all income at the intermediate rate, SD1 at the higher rate, SD2 at the advanced rate and SD3 at the top rate. Welsh rates currently match England’s, but the C prefix must still be correct.

How to Find and Check Your Tax Code

You can find your British tax codes, one for each job or pension, in four places:

• Your payslip: usually printed next to your National Insurance number.
• The HMRC app: shows your current code for each job or pension.
• Your HMRC online account: the “check your Income Tax” service shows the code and how HMRC worked it out.
• A Tax Code Notice: HMRC’s letter or online message when your code changes.

Online, you can also see your British tax codes from earlier years and sign up for email alerts when your code changes. When you check, compare the deductions HMRC lists with your real benefits, income and allowances. Errors usually come from out-of-date estimates or a job you have already left.

What Should My Tax Code Be? Worked Examples

These examples show how British tax codes work in practice, using 2026/27 rates for England and Northern Ireland: a £12,570 Personal Allowance, 20% basic rate and 40% higher rate.

Example 1: One job on 1257L

Amira earns £30,000 a year and is paid monthly. Her code 1257L gives £12,570 tax-free, or about £1,047 a month. Tax is 20% of £17,430, which is £3,486 a year, or about £290.50 a month.

Example 2: Second job on BR

Amira also earns £8,000 from weekend work. Her main job uses all her Personal Allowance, so the second job gets BR. Every pound is taxed at 20%, which is £1,600 for the year. That is correct, because the whole £8,000 falls inside her basic rate band.

Example 3: Company car

Daniel has a company car with a taxable benefit of £3,000. HMRC reduces his tax-free amount from £12,570 to £9,570, so his code becomes 957L. Payroll collects the tax on the car through his salary rather than through Self Assessment.

Example 4: Marriage Allowance

Priya transfers £1,260, which is 10% of her allowance, to her husband. Her code becomes 1131N and his becomes 1383M. He saves up to £252 a year in tax. You can apply through GOV.UK’s Marriage Allowance service.

What to Do If Your Tax Code Is Wrong

If your code looks wrong, act quickly. The sooner HMRC corrects it, the more evenly any overpayment or underpayment is spread across your remaining pay.

1. Check the deductions and estimated income in the HMRC app or your online account.
2. Update anything out of date, such as a benefit that has ended or a job you have left.
3. Contact HMRC by phone or webchat if you cannot fix it online.
4. Do not ask your employer to change the code; payroll must use the code HMRC issues.

Common errors in British tax codes include a BR code on your main job, an old employer still showing as live, and estimated income that is far higher than you really earn. If your tax affairs are more complex, our personal tax planning service can review your codes alongside your wider position.

Frequently Asked Questions

What is the standard tax code for 2026/27?

The standard code among British tax codes is 1257L. It gives a tax-free Personal Allowance of £12,570 from one job or pension and applies basic, higher and additional rates to the rest. Scottish taxpayers have S1257L and Welsh taxpayers C1257L.

What does BR mean on my tax code?

BR means all income from that job or pension is taxed at the 20% basic rate, with no tax-free amount. It is common on a second job. If your total income is below £12,570, ask HMRC to move some allowance across.

What does T mean in a tax code?

T means your code includes other calculations that HMRC needs to review with you. Tax is still deducted at the basic, higher or additional rate according to your pay. Check the breakdown in the HMRC app if you are unsure why it was used.

Why is my tax code 0T?

A 0T code means no Personal Allowance from that source. HMRC uses it when your allowance is used up, your income is over £125,140, or a new employer lacks your details. Giving your P45 often fixes it.

How do I check my tax code?

Look on your payslip, sign in to the HMRC app or your HMRC online account, or read your latest Tax Code Notice. The app and online account also show how your code was calculated and let you report changes.

Can my employer change my tax code?

No. Your employer must use the code HMRC sends. If you think it is wrong, contact HMRC or update your details online. Once HMRC changes the code, your employer will be told and will apply it to your next pay.

Final Verdict: Getting British Tax Codes Right Saves Money

British tax codes look cryptic, but they follow a simple pattern: a number for your tax-free pay and a letter for your situation. Check yours every April and whenever your work or benefits change. A two-minute check in the HMRC app can stop months of overpaid tax.