UK Tax Code Explained (2026 Guide): What Your Tax Code Means & How to Fix It

Your UK tax code determines how much Income Tax your employer or pension provider deducts from your pay. If your tax code is wrong, you could overpay tax or receive an unexpected HMRC bill later. This guide explains UK tax codes clearly, using official HMRC rules, practical examples, and current guidance for the 2026 to 2027 tax year.

Last reviewed: 2 September 2026. Tax codes and allowances can change, so check the latest HMRC guidance for your circumstances. For the official employee tax-code guidance, see GOV.UK: Understanding your tax code.

What Is a UK Tax Code?

A tax code is issued by HM Revenue & Customs (HMRC) and sent to your employer or pension provider. It tells them how much tax-free income you’re entitled to and how your income should be taxed.

Each job or pension you have usually comes with its own tax code. If you also complete Self Assessment, that is separate from the PAYE tax code used by your employer or pension provider. See our UK Self Assessment guide for filing deadlines and payment dates.

How to Read a UK Tax Code

UK tax codes contain numbers and letters, each with a specific meaning:

• Numbers show your tax-free Personal Allowance
• Letters explain your tax situation

Example:

1257L means:

• For 2026 to 2027, the standard Personal Allowance is £12,570 for most taxpayers
• You pay tax only on income above that amount

Common UK Tax Codes Explained

1257L – Standard Tax Code

1257L generally applies where you are entitled to the standard Personal Allowance and have one main job or pension with no adjustments such as untaxed income or taxable benefits. The standard Personal Allowance is £12,570 for 2026 to 2027.

0T – No Personal Allowance

Used when:

• Your allowance is used elsewhere
• HMRC lacks your employment details
• You start a new job without a P45

Tax is calculated on all taxable pay because no Personal Allowance is included in the code. The applicable rates depend on your income and tax jurisdiction; Scottish taxpayers may have an S-prefix code and Scottish Income Tax bands.

BR – Basic Rate Tax Code

All income from that employment or pension is taxed at the basic rate. It is commonly used for a second job or pension. The exact tax treatment depends on your tax jurisdiction.

• Second jobs
• Additional pensions

D0 & D1 – Higher Tax Rates

• D0: for a D0 code without an S prefix, all income from that employment or pension is taxed at the higher rate
• D1: for a D1 code without an S prefix, all income from that employment or pension is taxed at the additional rate

Often used when your Personal Allowance is already allocated.

M & N – Marriage Allowance

• M: You receive your partner’s unused allowance
• N: You transfer part of your allowance to your partner

Only available to eligible couples.

NT – No Tax

No tax deducted. Rare, but may apply in cases such as:

• Bankruptcy
• Certain non-resident situations

S & C – Scottish and Welsh Tax Codes

• S: Scottish income tax rates apply
• C: Welsh income tax rates apply

An S prefix means Scottish Income Tax rates apply to relevant wages and pension income. A C prefix means Welsh Income Tax rates apply. The applicable rules and bands differ from those used elsewhere in the UK, so check the current GOV.UK guidance.

Special UK Tax Codes

T – Special Circumstances

Used when HMRC needs to calculate tax manually, often due to:

• Untaxed income
• Benefits in kind

K – Tax on Benefits

Used when taxable benefits exceed your Personal Allowance.
Your employer deducts extra tax directly from your salary.

Emergency Tax Codes (W1, M1, X)

These suffixes show that tax is being calculated on a non-cumulative basis while HMRC or your employer obtains updated information. W1 is generally used for weekly pay, M1 for monthly pay, and X where pay dates vary. An emergency code can result in too much or too little tax, so it does not automatically mean you will receive a refund.

HMRC official guidance: understanding employee tax codes and emergency tax codes.

HMRC Personal Tax Account:
https://www.gov.uk/personal-tax-account

Income tax rates UK:
https://www.gov.uk/income-tax-rates

How to Check Your UK Tax Code

You can find your tax code on:

• Your payslip
• P45 or P60
• Your HMRC Personal Tax Account
• The HMRC app

What to Do If Your Tax Code Is Wrong

If something looks incorrect:

1. Log in to your HMRC Personal Tax Account
2. Check income and employment details
3. Contact HMRC directly if needed

If the details are wrong or missing, update them through HMRC’s online service or contact HMRC. HMRC can then issue a revised tax code to you and your employer or pension provider, which should use the revised code when it receives it.

Why UK Tax Codes Change

Your tax code may change if you:

• Start or leave a job
• Get a pay rise
• Receive company benefits
• Take a second job
• Move between England, Scotland, or Wales

HMRC may change your tax code when your job, pension, benefits, estimated income, savings interest, expenses or other circumstances change. Check the reason in your HMRC account and tell HMRC if the information is wrong or incomplete.

How to Avoid Overpaying or Underpaying Tax

• Review payslips monthly
• Update HMRC when circumstances change
• Use HMRC’s income tax checker
• Seek professional tax advice if unsure

Frequently Asked Questions (FAQ)

Can I have more than one tax code?

Yes. Each job or pension may have a different tax code.

Can I change my tax code myself?

No, but you can update your details with HMRC and request a review.

What happens if I pay too much tax?

HMRC will issue a refund, usually automatically.

How long do emergency tax codes last?

Until HMRC receives correct income details.

Final Thoughts

Understanding your UK tax code helps you avoid mistakes, refunds delays, and unexpected tax bills. Checking your tax code regularly ensures you pay exactly what you owe – no more, no less.

For complex situations such as multiple incomes or benefits, professional advice can save time and money.