Last updated: April 2026 · Reflects 2026/27 tax year
UK Tax Codes Explained: What Your Tax Code Means and How to Check It (2026/27)
Your tax code tells your employer how much income tax to deduct from your pay. Here's a plain-English guide to every letter, number, and prefix — plus how to check yours is correct.
Quick Summary
1257L
Standard tax code for most employees in 2026/27
Letters
Each letter defines your tax situation (L, BR, K, S, etc.)
Free Tool
Check yours instantly with our Tax Code Checker
What Is a Tax Code?
A tax code is a short combination of numbers and letters that tells your employer how much income tax to deduct from your wages. HMRC issues your tax code based on your personal circumstances — your allowances, any untaxed income, and whether you owe tax from a previous year.
The structure is straightforward: the number represents your tax-free allowance (divided by 10), and the letter tells your employer which set of rules to apply. For example, 1257L means you have a tax-free allowance of £12,570 and the standard “L” rules apply.
Your employer uses this code every time they run payroll. If the code is wrong, you could end up paying too much or too little tax throughout the year. You can find your current code on your payslip, P45, P60, or by logging into your HMRC online tax account.
Example: If your tax code is 1257L, the number 1257 multiplied by 10 gives £12,570 — that's your Personal Allowance. You won't pay income tax on the first £12,570 you earn. Everything above that is taxed at the applicable rates.
The Numbers in Your Tax Code Explained
The number in your tax code represents your tax-free allowance for the year. Multiply the number by 10 to get the actual amount. The standard Personal Allowance for 2026/27 is £12,570, which gives the number 1257 in most people's tax codes.
However, your number might be different from 1257. Here's why it can vary:
Higher than 1257
You have extra tax-free allowance. This can happen if you receive Marriage Allowance from your spouse (adding ~125 to your code), or if you have professional subscriptions or work expenses that HMRC has approved.
Lower than 1257
Your allowance has been reduced. Common reasons include company benefits (company car, private medical insurance), untaxed state pension income, or tax owed from a previous year being collected through your code.
No number at all (e.g. BR, D0, NT)
Some codes have no number because they apply a flat rate to all your income from that employer. BR means everything is taxed at 20%, D0 at 40%. These are common for second jobs.
Tip: If you earn over £100,000, your Personal Allowance is reduced by £1 for every £2 over £100k. At £125,140 it disappears entirely, which is why high earners often see tax codes like 0T. Read more about this in our guide to the £100k tax trap.
Common Tax Code Letters and What They Mean
The letter (or letters) at the end of your tax code tells your employer which rules to follow when calculating your tax. Here is a complete guide to every letter you might see:
| Code | Meaning | Who Gets It |
|---|---|---|
| L | Standard Personal Allowance | Most employees — the most common tax code letter |
| M | Marriage Allowance recipient (extra 10%) | You received a transfer of £1,260 from your spouse's allowance |
| N | Marriage Allowance transferor (reduced by 10%) | You transferred £1,260 of your allowance to your spouse |
| T | HMRC needs to review items in your code | Used when there are items HMRC wants to check or unusual circumstances |
| BR | All income taxed at basic rate (20%) | Typically a second job where your allowance is used by your main employer |
| D0 | All income taxed at higher rate (40%) | Second job where your main income is already in the higher-rate band |
| D1 | All income taxed at additional rate (45%) | Second job where your main income exceeds £125,140 |
| 0T | No Personal Allowance | Income over £125,140 (allowance fully tapered), or new starter without a P45 |
| K | Deductions exceed your allowance | Benefits in kind (company car, medical) worth more than your tax-free amount |
| NT | No tax to be deducted | Rare — used for certain types of income that are not taxable |
| S | Scottish taxpayer prefix | You live in Scotland — Scottish income tax rates apply |
| C | Welsh taxpayer prefix | You live in Wales — currently the same rates as England |
You can decode your tax code instantly using our free Tax Code Checker. Just enter your code and it will explain exactly what each part means and flag any potential issues. For the official HMRC reference, see the GOV.UK tax codes guide.
Scottish and Welsh Tax Codes
If you live in Scotland, your tax code will start with the letter S (e.g. S1257L). This tells your employer to apply Scottish income tax rates instead of the rest-of-UK rates. Scotland has six tax bands ranging from 19% (Starter rate) to 48% (Top rate), compared to England's three bands.
Similarly, if you live in Wales, your code starts with C (e.g. C1257L). The Welsh Government has the power to set its own rates, but so far Welsh rates have been identical to England's. The C prefix simply identifies you as a Welsh taxpayer for administrative purposes.
Your residency is determined by where you live on 5 April each year — not where you work. If you live in Edinburgh but commute to a job in Newcastle, you're a Scottish taxpayer and will have an S prefix.
Important: The S and C prefixes only affect income tax on employment and pension income. National Insurance, dividend tax, and savings interest tax are the same across the whole UK. To see exactly how Scottish and English tax bills compare, read our Scottish tax vs English tax comparison.
Emergency Tax Codes: W1, M1, and X
If you see W1 (week 1), M1 (month 1), or X at the end of your tax code, you're on an emergency tax code. This means your employer is calculating your tax on a non-cumulative basis — each pay period is treated in isolation, without accounting for your earnings earlier in the year.
Emergency codes are usually applied when you start a new job and HMRC doesn't yet have your full tax details. Common triggers include:
- Starting a new job without providing a P45 from your previous employer
- Starting your first job ever
- Receiving company benefits or the State Pension for the first time
- Taking a pension withdrawal (emergency rate often applies to lump sums)
In most cases, the emergency code resolves automatically once HMRC receives your information and issues your correct code. This can take a few weeks. If it persists beyond two or three pay periods, contact HMRC with your P45 or P60 to get it corrected.
Watch out: Emergency tax codes can cause you to overpay tax, especially in the months before the correct code is issued. If this happens, you'll usually get a refund automatically when your code is corrected. If not, you can claim a tax refund from HMRC.
K Codes Explained
A K code is used when the value of your benefits in kind and other deductions exceeds your tax-free Personal Allowance. Unlike normal tax codes where the number represents your allowance, a K code works in reverse — the number is added to your taxable income rather than deducted from it.
For example, if your tax code is K497, it means £4,970 is added to your taxable income. This can happen when the combined value of your company car, private medical insurance, interest-free loans, or other taxable benefits exceeds £12,570.
K codes are also used when you have unpaid tax from a previous year that HMRC is collecting through your pay, or when you receive the State Pension alongside employment income and the combined amount pushes your deductions above your allowance.
Protection rule: Even with a K code, your employer cannot deduct more than 50% of your gross pay in tax. This is a legal safeguard to ensure you always take home at least half your wages, regardless of how large the K code number is.
How to Check Your Tax Code
It's worth checking your tax code at least once a year, especially after changing jobs, receiving new benefits, or at the start of each tax year in April. Here are three ways to check:
Find it on your payslip or P45/P60
Your tax code appears on every payslip, usually near the top alongside your NI number. It also appears on your P45 (when you leave a job), P60 (end-of-year statement), and any tax coding notice from HMRC.
Use our free Tax Code Checker tool
Enter your tax code into our Tax Code Checker and get an instant breakdown of what each part means, your estimated allowance, and any warnings if something looks unusual.
Check via HMRC online
Sign in to your personal tax account on GOV.UK to see your current tax code, how it was calculated, and how much tax you've paid so far this year.
Pro tip: If you have multiple jobs, you'll have a separate tax code for each employer. Your Personal Allowance is usually applied to your main job (1257L), while second jobs typically get BR or D0. Use our Two Jobs Calculator to see how your tax works across multiple employments.
What to Do If Your Tax Code Is Wrong
If you think your tax code is incorrect, it's important to act quickly. A wrong code can mean you're overpaying tax (losing money each month) or underpaying (leading to a bill later). Common reasons for an incorrect code include:
- Your employer sent HMRC the wrong information about your benefits
- You changed jobs and your P45 details weren't passed on correctly
- You started or stopped receiving a taxable benefit (company car, medical insurance)
- You have untaxed income that HMRC doesn't know has stopped
- Marriage Allowance was applied incorrectly or not at all
To get your code corrected, you can contact HMRC by phone on 0300 200 3300 (Monday to Friday, 8am to 6pm) or update your details through your personal tax account on GOV.UK. HMRC will then issue a new tax code to your employer, and any overpaid tax should be refunded through your pay.
Refund timeline: If you've overpaid, the refund usually appears in your next payslip after your employer receives the corrected code. If the tax year has already ended, you may need to submit a P800 tax refund claim.
Tips to Make the Most of Your Tax Code
While you can't directly choose your tax code, there are legitimate steps you can take to ensure you're getting the correct allowances and not paying more tax than necessary:
Claim Marriage Allowance
If you're married or in a civil partnership and one partner earns under £12,570, they can transfer £1,260 of their allowance to the other partner. This saves the recipient up to £252 per year. You can backdate claims for up to 4 years.
Check Benefits in Kind Are Correct
If your company car has changed, you've given up private medical insurance, or any other benefit has ended, make sure HMRC knows. Outdated benefit information is one of the most common causes of wrong tax codes.
Consider Salary Sacrifice
Salary sacrifice for pension contributions, cycle-to-work schemes, or electric cars reduces your taxable income before PAYE is calculated. This can bring you into a lower tax band and effectively change the tax you pay.
Review After Job Changes
Every time you change jobs, check your tax code on your first payslip from the new employer. Errors are most common during transitions, especially if your P45 details are delayed or incorrect. Use our Take Home Pay Calculator to verify your expected pay matches your actual payslip.
Frequently Asked Questions
What does tax code 1257L mean?
1257L is the standard tax code for most employees in 2026/27. The number 1257 means your tax-free Personal Allowance is £12,570 (1257 × 10). The letter L means you're entitled to the standard Personal Allowance with no special circumstances. This code has been the standard since 2021/22 because the Personal Allowance has been frozen at £12,570.
What does the letter in my tax code mean?
The letter tells your employer which rules to apply. L means the standard allowance, M and N relate to Marriage Allowance, BR means all income is taxed at 20% (common for second jobs), K means your deductions exceed your allowance so the amount is added to your income, and S or C prefixes indicate Scottish or Welsh taxpayer status respectively.
What is an emergency tax code?
An emergency tax code (indicated by W1, M1, or X at the end) means HMRC doesn't have your complete tax information yet. Your employer taxes each pay period in isolation rather than cumulatively. This often happens when you start a new job without a P45. It usually resolves within a few weeks once HMRC receives your details.
What does a K tax code mean?
A K code means the value of your untaxed benefits and deductions is greater than your Personal Allowance. Instead of reducing your taxable income, the number in a K code is added to it. For example, K497 adds £4,970 to your taxable income. K codes are common for people with significant company benefits like cars or who receive both a salary and the State Pension.
How do I check if my tax code is correct?
You can check your tax code on your payslip, P45, or P60. Use our free Tax Code Checker to decode what it means instantly. You can also sign into your personal tax account on GOV.UK to see the full breakdown of how HMRC calculated your code and report any errors.
What does the S prefix mean on my tax code?
The S prefix (e.g. S1257L) means you're classified as a Scottish taxpayer and Scottish income tax rates apply to your employment income. Scotland has six tax bands ranging from 19% to 48%, which differ from England's three bands. Your Scottish status is based on where you live on 5 April, not where you work.
Can I change my tax code?
You can't directly choose your tax code, but you can ask HMRC to review and correct it if you believe it's wrong. Contact HMRC on 0300 200 3300 or update your details through your personal tax account on GOV.UK. If your circumstances change (new benefits, Marriage Allowance, job changes), HMRC should update your code automatically, but it's worth checking they have.
Check Your Tax Code Now
Enter your tax code into our free checker tool and get an instant plain-English explanation of what it means, your estimated allowance, and any warnings.
Try the Tax Code Checker →Disclaimer: This article is for informational purposes only and does not constitute financial or tax advice. Tax rules can change and individual circumstances vary. Always consult a qualified accountant or tax adviser before making financial decisions based on this information. Data reflects the 2026/27 tax year unless stated otherwise.