Your tax code determines how much income tax is deducted from your salary each month. For teachers, getting the right tax code is essential — an incorrect code can mean you pay too much or too little tax, potentially leading to unexpected bills or refund claims. This guide explains the most common tax codes, what the letters and numbers mean, how to check your code, common errors that affect teachers, and how to contact HMRC if something is wrong.
The Standard Tax Code: 1257L
The most common tax code in England and Wales is 1257L. This code means you have a tax-free Personal Allowance of £12,570 per year. The number in the code (1257) represents the allowance divided by 10, and the letter L indicates that you are entitled to the standard Personal Allowance with no adjustments.
With tax code 1257L, you pay no income tax on the first £12,570 of your annual earnings. Income above this threshold is taxed at the basic rate (20%) up to £50,270, and at the higher rate (40%) between £50,270 and £125,140. For the vast majority of classroom teachers on the Main Pay Range, all taxable income falls within the 20% basic rate band.
| Band | Threshold | Rate |
|---|---|---|
| Personal Allowance | Up to £12,570 | 0% |
| Basic rate | £12,570 - £50,270 | 20% |
| Higher rate | £50,270 - £125,140 | 40% |
When 1257L Applies
Common Tax Codes for Teachers
While 1257L is the standard, teachers may encounter several other tax codes depending on their circumstances:
BR — Basic Rate
The code BR means all your income from this employment is taxed at the basic rate of 20%, with no Personal Allowance applied. This is typically used for a second job. If you do supply teaching alongside a permanent role, your supply work might be coded BR because your Personal Allowance is already being used against your main teaching salary. This is correct — your allowance can only be applied to one source of income.
D0 — Higher Rate
The code D0 means all your income from this employment is taxed at the higher rate of 40%. This would apply to a second job where your main employment already uses up both your Personal Allowance and basic rate band. For example, if your main teaching salary is £55,000, your basic rate band is fully used, and any second income would be taxed at 40%. D0 is relatively unusual for classroom teachers but may apply to those in senior leadership roles with additional income sources.
K Codes — Negative Allowance
A K code (e.g., K475) is used when the value of your taxable benefits and deductions exceeds your Personal Allowance. The K prefix means HMRC is adding income to your taxable pay rather than deducting an allowance. This can happen if you have significant taxable benefits such as a company car, private medical insurance, or if you owe tax from previous years that HMRC is collecting through your code.
For teachers, K codes are uncommon but can arise if you have untaxed income from another source (such as rental property income) that HMRC has decided to collect through your PAYE code. If you are placed on a K code unexpectedly, contact HMRC to understand why and check that the calculation is correct.
S Prefix — Scotland
If you live in Scotland, your tax code will begin with the letter S (e.g., S1257L). This indicates that Scottish income tax rates and bands apply. Scotland has different tax rates from the rest of the UK: a starter rate of 19%, a basic rate of 20%, an intermediate rate of 21%, a higher rate of 42%, an advanced rate of 45%, and a top rate of 48%. The rates and bands are set by the Scottish Parliament and can change independently of rUK rates.
Your S prefix is determined by where you live, not where you work. A teacher living in Scotland but working in an English school near the border would still pay Scottish income tax. HMRC determines your country of residence for tax purposes based on your registered address.
C Prefix — Wales
If you live in Wales, your tax code will begin with the letter C (e.g., C1257L). Welsh income tax rates are currently the same as those in England and Northern Ireland, but the Welsh Government has the power to vary rates independently. The C prefix allows HMRC to identify Welsh taxpayers should the rates diverge in future. As with Scotland, the prefix is based on your residential address.
W1 / M1 — Week 1 / Month 1 (Emergency Tax)
If your tax code has a W1 or M1 suffix (e.g., 1257L W1 or 1257L M1), you are on an emergency or non-cumulative tax code. This means HMRC calculates your tax based only on the current pay period, without accounting for your cumulative earnings and tax paid so far in the year. This often happens when you start a new job and your previous employer has not yet sent your P45 to the new school.
Emergency tax codes usually result in overpaying tax, because the cumulative calculation normally ensures your Personal Allowance is spread evenly across the year. Once HMRC receives your correct information (typically via your P45 or a new starter checklist), your code will be updated and any overpaid tax refunded through your payslip. If the emergency code persists beyond your first two payslips, contact your school's payroll team.
New Job? Check Your Tax Code
How to Check Your Tax Code
There are several ways to check your current tax code:
- Payslip: Your tax code is printed on every payslip, usually in the "Tax" or "Deductions" section. Check it each month, especially after changing jobs or at the start of the tax year in April.
- P60: Your P60, issued by your employer after the end of each tax year (by 31 May), shows your tax code and total tax paid during the year.
- HMRC Personal Tax Account: You can view your current tax code, check your income and tax for the current year, and see your coding notice online through your HMRC Personal Tax Account at gov.uk/personal-tax-account.
- HMRC App: The free HMRC app provides the same information as the online Personal Tax Account and is available for iOS and Android.
- Tax Coding Notice (P2): HMRC sends a P2 coding notice by post or to your Personal Tax Account whenever your tax code changes. This document explains how your code has been calculated and lists any adjustments.
Common Tax Code Errors for Teachers
Teachers are particularly susceptible to certain tax code errors due to the nature of the profession:
Duplicate Employment Records
If you work at multiple schools (e.g., main role plus supply work) or change schools mid-year, HMRC may incorrectly split your Personal Allowance between employers or fail to close a previous employment record. This can result in being overtaxed or undertaxed. Check that your Personal Tax Account shows the correct number of employments and that your allowance is allocated to the right employer.
Incorrect Benefits or Underpayments
HMRC may add estimated benefits or carry forward an underpayment from a previous year, reducing your tax-free allowance and giving you a lower number in your tax code (e.g., 1100L instead of 1257L). If you do not have the taxable benefits HMRC thinks you have, contact them to correct the record.
Marriage Allowance Transfer
If you or your spouse has transferred part of the Personal Allowance through the Marriage Allowance, your tax code will be adjusted. The transferor's code will show a lower allowance (e.g., 1007L), while the recipient's code will be higher (e.g., 1507L). Ensure this is still correct if your circumstances have changed — for example, if the lower-earning partner's income has risen above the basic rate threshold.
How to Contact HMRC About Your Tax Code
If you believe your tax code is wrong, you can contact HMRC through:
- Online: Through your HMRC Personal Tax Account — you can check your code and submit a query.
- Phone: HMRC Income Tax helpline on 0300 200 3300 (Monday to Friday, 8am to 6pm).
- Post: Write to Pay As You Earn and Self Assessment, HM Revenue and Customs, BX9 1AS.
When contacting HMRC, have your National Insurance number, current tax code, and a recent payslip to hand. If you have overpaid tax due to an incorrect code, HMRC will issue a refund — either through an adjusted tax code in the current year or as a direct repayment via cheque or bank transfer.
Professional Subscription Tax Relief
Understanding your tax code is a fundamental part of managing your finances as a teacher. Use our take-home pay calculator to see how your tax code affects your monthly income, and check the pay scales page to understand your gross salary at each pay point.