2026/27 Tax Year

UK Tax Codes Explained: 1257L, BR, D0, K, OT & Emergency Codes

What every code means, how to check yours, and what to do if it's wrong
Last Updated9 May 2026

Your tax code determines how much Income Tax your employer deducts from your salary. A single wrong digit can cost you hundreds of pounds per year — yet most people never check theirs. This guide explains every common UK tax code for 2026/27 and how to make sure yours is correct.

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What Is a Tax Code?

A tax code is a combination of numbers and letters that tells your employer how much tax-free income (Personal Allowance) you're entitled to each year. HMRC issues your tax code based on information they hold about your income, benefits and circumstances.

Your employer uses this code to calculate how much tax to deduct from each payslip. If your code is wrong, you either overpay tax (and should claim a refund) or underpay (and will owe HMRC money, usually collected through a future tax code adjustment).

What Does 1257L Mean?

The most common tax code in the UK is 1257L. Here's how to read it:

1257L

1257 = Tax-free amount of £12,570 per year (the standard Personal Allowance)
L = You're entitled to the standard tax-free Personal Allowance

For 2026/27, the standard Personal Allowance is £12,570. This means you pay no Income Tax on the first £12,570 you earn. Earnings above this are taxed at 20% (Basic Rate) up to £50,270, then 40% (Higher Rate) up to £125,140, and 45% (Additional Rate) above that.

Tax Code Letters Explained

LetterMeaningWhen Used
LStandard Personal AllowanceMost employees with one job
MMarriage Allowance receivedYou've received 10% of partner's allowance
NMarriage Allowance transferredYou've given 10% to your partner
TOther calculationsComplex tax situations
KOwed tax > allowanceUntaxed income exceeds allowance
BRBasic Rate (20%)Second jobs
D0Higher Rate (40%)Second jobs, high earners
D1Additional Rate (45%)Income > £125,140
NTNo taxVery specific circumstances
0TNo Personal AllowanceEmergency / high earner

Common Tax Codes Explained

1257L — Standard Code

You have the full £12,570 Personal Allowance. Most employees start here. If your income exceeds £100,000, the number decreases as your allowance tapers.

BR — Basic Rate (20% on everything)

Used for second jobs. You pay 20% tax on all earnings because your Personal Allowance is used elsewhere.

D0 — Higher Rate (40% on everything)

Used when your total income from all sources exceeds £50,270. All earnings from this job are taxed at 40%.

K Code — You owe more than your allowance

A K code means your untaxed income (benefits, state pension, etc.) exceeds your Personal Allowance. The number after K is the additional amount to be taxed, divided by 10. For example, K500 means £5,000 of untaxed income on top of your salary.

OT — No Personal Allowance

All income is taxed. Used as an emergency code or for very high earners who've lost their entire Personal Allowance (income above £125,140).

Emergency Tax Codes

When you start a new job, HMRC may not have your details yet. Your employer will use an emergency tax code temporarily:

Emergency tax usually results in overpaying tax. HMRC will automatically refund you or adjust your code once they have your correct information.

How to Check Your Tax Code

You can find your tax code on:

What If My Tax Code Is Wrong?

Contact HMRC on 0300 200 3300 with your National Insurance number. You can also update your details through your Personal Tax Account.

If you've overpaid, HMRC will either send a refund (P800) or adjust your tax code to give you the money back gradually. If you've underpaid, they'll usually collect it through your tax code over the next tax year.

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Frequently Asked Questions

What does tax code 1257L mean?
1257L is the standard UK tax code. 1257 means a tax-free Personal Allowance of £12,570/year. L means you get the standard allowance. Your employer only deducts tax on earnings above £12,570.
Why has my tax code changed to BR?
BR means 20% tax on all earnings. HMRC uses it for second jobs because your Personal Allowance is used against your main job. If BR is on your ONLY job, contact HMRC immediately.
What is an emergency tax code?
Temporary codes (0T, W1/M1, or BR) used when HMRC lacks your information. Common when starting a new job. Usually results in overpaying tax — claim a refund once your correct code is applied.
How do I know if my tax code is wrong?
Signs: multiple jobs earning over £50k combined, taxable benefits not reflected, job change without P45, significant income change. Check your payslip or P800. Use our Tax Code Checker to verify.
What should I do if my tax code is wrong?
Contact HMRC on 0300 200 3300 with your NI number, or use your Personal Tax Account at gov.uk. Overpayments are refunded via P800 or tax code adjustment. Keep records of all communication.

Sources & Methodology

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