Tax Code Calculator 2025/26

How to Use This Calculator

Our tax code calculator helps you understand exactly what your HMRC tax code means and how it affects your take-home pay. Follow these simple steps to decode your tax code and see a full breakdown of your tax position for the 2025/26 tax year.

Step 1: Find Your Tax Code

Your tax code appears on your payslip, P45, P60, or any HMRC correspondence. It is usually a combination of numbers and letters, such as 1257L. You can also find it by logging in to your Personal Tax Account on GOV.UK.

If you have a Scottish or Welsh prefix (S or C), include that as well. Emergency suffixes like W1 or M1 should also be entered exactly as they appear.

Step 2: Enter Your Tax Code

Type your full tax code into the input field at the top of this page. You can enter codes in any format -- for example, 1257L, BR, K475, S1257L, or 1257L M1. The calculator accepts all standard HMRC tax codes including special codes like D0, D1, NT, and 0T. Alternatively, click one of the common tax codes shown below the calculator to decode it instantly.

Step 3: View Your Breakdown

After clicking "Decode Tax Code", you will see a detailed explanation of what each part of your code means, including your tax-free Personal Allowance and any adjustments. The status badge indicates whether your code is standard, reduced, or an emergency code that may need attention.

Step 4: Calculate Your Tax Impact

For a complete picture, enter your annual gross salary in the "How Does Your Tax Code Affect Your Pay?" section. The calculator will show your annual income tax, National Insurance contributions, and take-home pay broken down by year, month, and week. It also compares your tax position against the standard 1257L code so you can see if you are paying more or less tax than a typical employee.

Worked Examples: Tax Code Calculations

These examples show how different tax codes affect your income tax for the 2025/26 tax year. All calculations use the standard England, Wales, and Northern Ireland tax bands: 20% basic rate (up to £37,700 of taxable income), 40% higher rate (£37,701 to £125,140), and 45% additional rate (over £125,140).

Example 1: Tax Code 1257L on a £30,000 Salary

This is the most common scenario for UK employees with one job and no benefits in kind.

• Tax code: 1257L (standard Personal Allowance)
• Personal Allowance: 1257 x 10 = £12,570 tax-free
• Taxable income: £30,000 - £12,570 = £17,430
• Income tax: £17,430 x 20% = £3,486.00 per year
• Monthly tax: £3,486 / 12 = £290.50
• Take-home (before NI): £30,000 - £3,486 = £26,514 per year

All £17,430 of taxable income falls within the basic rate band (up to £37,700), so only the 20% rate applies.

Example 2: Tax Code BR on a £12,000 Second Job

BR is commonly used for a second job where your Personal Allowance is already applied to your main employment.

• Tax code: BR (Basic Rate -- no Personal Allowance)
• Personal Allowance: £0 (already used on main job)
• Taxable income: £12,000 (entire salary is taxable)
• Income tax: £12,000 x 20% = £2,400.00 per year
• Monthly tax: £2,400 / 12 = £200.00

With a BR code, every pound you earn from this job is taxed at the basic rate of 20%. This is correct if your full Personal Allowance is allocated to your primary job. If you are not using your full allowance elsewhere, contact HMRC to redistribute it.

Example 3: Tax Code K475 on a £40,000 Salary

K codes are used when your deductions (such as company benefits or underpaid tax from previous years) exceed your Personal Allowance. Instead of giving you a tax-free amount, the K code adds to your taxable income.

• Tax code: K475 (deductions exceed allowance)
• Additional taxable amount: 475 x 10 = £4,750 added to income
• Taxable income: £40,000 + £4,750 = £44,750
• Income tax: £37,700 x 20% = £7,540.00 (basic rate) + £7,050 x 40% = £2,820.00 (higher rate) = £10,360.00
• Monthly tax: £10,360 / 12 = £863.33

In this example, the employee might have a company car, private medical insurance, or owe tax from a previous year, causing their deductions to total more than £12,570. HMRC collects the shortfall by adding £4,750 to the taxable income.

Example 4: Tax Code 1185L on a £35,000 Salary

A reduced Personal Allowance typically occurs when you receive benefits in kind from your employer or owe tax from a prior year.

• Tax code: 1185L (reduced allowance due to benefits)
• Personal Allowance: 1185 x 10 = £11,850 tax-free
• Reduction from standard: £12,570 - £11,850 = £720 (value of benefits being taxed)
• Taxable income: £35,000 - £11,850 = £23,150
• Income tax: £23,150 x 20% = £4,630.00 per year
• Monthly tax: £4,630 / 12 = £385.83

Compared to the standard 1257L code, this employee pays an extra £144.00 per year in tax (£720 x 20%). If the benefit causing the reduction no longer applies, you should contact HMRC to have your code updated.

Example 5: Tax Code 0T on a £28,000 Salary

The 0T code means you have no Personal Allowance. This is often an emergency tax code used when HMRC does not have enough information, or when your income exceeds £125,140 and your allowance has been fully tapered away.

• Tax code: 0T (no Personal Allowance)
• Personal Allowance: £0
• Taxable income: £28,000 (entire salary is taxable)
• Income tax: £28,000 x 20% = £5,600.00 per year
• Monthly tax: £5,600 / 12 = £466.67

On a £28,000 salary, a 0T code means you pay £2,114.00 more tax per year than someone on the standard 1257L code (£5,600 vs £3,486). If you are on a 0T code and believe you are entitled to the standard Personal Allowance, check your tax code through your Personal Tax Account or contact HMRC on 0300 200 3300 as soon as possible.

Understanding Your Tax Code in Detail

Every UK employee and pensioner is assigned a tax code by HMRC. Your tax code determines how much income tax your employer or pension provider deducts from your pay each period. Understanding each component of your code is essential to ensuring you pay the correct amount of tax.

What the Numbers Mean

The numbers in your tax code represent your tax-free Personal Allowance. To find your actual allowance, multiply the number by 10. For example, 1257 means you can earn £12,570 before paying any income tax.

If your code shows a lower number, such as 1100, your allowance has been reduced to £11,000 -- likely because HMRC is collecting tax on benefits in kind or recovering underpaid tax from previous years. A higher number, such as 1382, means you have an increased allowance, perhaps due to receiving Marriage Allowance from your partner or qualifying for Blind Person's Allowance.

What Each Letter Suffix Means

The letter at the end of your tax code tells your employer which category of Personal Allowance you are entitled to and how to calculate your tax:

• L -- You are entitled to the standard Personal Allowance. This is the most common code suffix, used by employees with one job and no special circumstances.
• M -- You have received a transfer of 10% of your partner's Personal Allowance through the Marriage Allowance scheme, giving you an extra £1,260 tax-free.
• N -- You have transferred 10% of your Personal Allowance to your partner under Marriage Allowance, reducing your tax-free amount by £1,260.
• T -- Your tax code includes other calculations to determine your Personal Allowance. HMRC may use this when your situation is more complex or when your allowance is being tapered due to income above £100,000.
• 0T -- You have no Personal Allowance. This can mean your allowance has been completely used up, you earn over £125,140, or HMRC needs more information about your circumstances. You should check this is correct.
• BR -- All income from this employment is taxed at the basic rate of 20%, with no Personal Allowance applied. Commonly used for second jobs or pensions.
• D0 -- All income from this employment is taxed at the higher rate of 40%. This is typically used for a second job when your main employment already covers the basic rate band.
• D1 -- All income from this employment is taxed at the additional rate of 45%.
• K -- Your deductions and benefits in kind exceed your Personal Allowance. The K code number, multiplied by 10, is added to your taxable income rather than subtracted from it.
• NT -- No tax is deducted from this income. This is used in specific circumstances, for example for certain non-taxable payments.

Scottish and Welsh Tax Codes

If you live in Scotland, your tax code will have an S prefix (for example, S1257L). Scottish taxpayers pay different income tax rates set by the Scottish Parliament. For 2025/26, Scotland has six income tax bands: starter rate (19%), basic rate (20%), intermediate rate (21%), higher rate (42%), advanced rate (45%), and top rate (48%). The personal allowance remains the same as the rest of the UK.

If you live in Wales, your tax code will have a C prefix (for example, C1257L). The Welsh Government has the power to set Welsh rates of income tax. For 2025/26, Welsh rates are the same as England and Northern Ireland, but the C prefix identifies you as a Welsh taxpayer in HMRC records.

What W1/M1 (Emergency or Non-Cumulative) Means

If your tax code has a W1 (Week 1) or M1 (Month 1) suffix, it means your tax is being calculated on a non-cumulative basis. Normally, your employer calculates your tax cumulatively throughout the year, taking into account all your earnings and tax paid so far. With a W1 or M1 code, each pay period is treated in isolation -- as if it were the first week or month of the tax year.

This can result in overpaying or underpaying tax compared to the cumulative method. Emergency W1/M1 codes are usually temporary and are applied when you start a new job without a P45, or when HMRC is still processing your tax code. Once HMRC issues your correct cumulative code, your employer will adjust your tax automatically, and any overpayment is refunded through your pay.

The £100,000 Income Trap

If your adjusted net income exceeds £100,000, your Personal Allowance is reduced by £1 for every £2 of income above £100,000. This means your Personal Allowance is completely eliminated when your income reaches £125,140. Effectively, this creates a 60% marginal tax rate on income between £100,000 and £125,140 (40% income tax plus 20% from the lost allowance). Your tax code will reflect this reduced allowance with a lower number, a T suffix, or even a 0T code if your allowance is fully removed.

Common Tax Code Problems and How to Fix Them

HMRC estimates that millions of UK taxpayers are on an incorrect tax code at any given time. Here are the most common problems and what you can do about them.

Wrong Tax Code on Your Payslip

If the tax code on your payslip does not look right, the first step is to check your Personal Tax Account on GOV.UK. This will show you a breakdown of how HMRC calculated your code, including any allowances, deductions for company benefits, or adjustments for underpaid tax. If any of the information is incorrect -- for example, a company car benefit that no longer applies -- you can update it online. HMRC will then issue a corrected code to your employer, usually within a few weeks.

Emergency Tax Codes

If you have recently started a new job, you may find yourself on an emergency tax code such as 1257L W1, 1257L M1, or even 0T. This typically happens because your new employer has not received your P45 from your previous job, and HMRC does not yet have the information needed to assign your correct code. To resolve this, provide your new employer with your P45 as quickly as possible or complete a Starter Checklist. HMRC will usually correct your code within 2 to 6 weeks, and any overpaid tax will be refunded automatically through your subsequent pay.

Tax Codes with Multiple Jobs

If you have two or more jobs, HMRC allocates your entire Personal Allowance to one employer (usually your main job, coded 1257L) and assigns a BR, D0, or D1 code to your additional employment. If HMRC splits the allowance incorrectly -- for example, giving your allowance to a low-paying second job while your main job has a BR code -- you may overpay or underpay tax. You can request HMRC to reallocate your allowance through your Personal Tax Account or by phoning 0300 200 3300.

Company Benefits Affecting Your Tax Code

Benefits in kind such as a company car, fuel benefit, private medical insurance, or interest-free loans reduce your Personal Allowance and change your tax code accordingly. If you stop receiving a benefit -- for example, you return a company car -- but your tax code is not updated, you will continue to overpay tax. Always inform HMRC promptly when your benefits change.

You can do this through your Personal Tax Account, or your employer should report the change on their P11D submission. If you have already overpaid, you can claim a refund through HMRC.