Teacher Tax Codes Explained (2026/27)

What the number in your tax code means

GOV.UK puts it simply: the numbers in your tax code tell your employer or pension provider how much tax-free income you get from them in that tax year. HMRC starts with your Personal Allowance, which is £12,570 for 2026/27 and has been frozen at that figure since April 2021, then adds anything that increases your tax-free amount and subtracts anything that reduces it. The resulting figure has its last digit removed to produce the number in the code.

GOV.UK's own worked example is a good illustration of a reduction. Someone entitled to the standard £12,570 allowance who also receives medical insurance worth £1,570 from their employer has the benefit taken off the allowance, "leaving you with a tax-free amount of £11,000. This would mean your tax code is 1100L."

The same machinery runs in the other direction. If HMRC has agreed an employment expenses claim — for most teachers, a union or professional body subscription — that amount is added to your tax-free figure, so your code rises slightly above 1257L. A teacher with £161 of allowable subscription relief would expect a code around 1273L.

What the letters mean

The letter is the shorthand for what kind of situation you are in. These are the ones a teacher realistically encounters, quoted from GOV.UK's own definitions.

W1, M1 and X: the emergency suffixes

A code ending in W1, M1 or X — sometimes shown on a payslip as NONCUM — is an emergency code. GOV.UK: W1 is "used when you're paid weekly", M1 "when you're paid monthly", and X "when your pay dates vary". The critical word is non-cumulative: "if you're on an emergency tax code your tax is worked out based on what you're paid in that week or month only", ignoring any unused allowance built up earlier in the tax year.

That matters disproportionately in teaching because the profession's main start date is September, five months into the tax year, with five months of unused Personal Allowance sitting there that an emergency code will not apply. HMRC normally issues the correct cumulative code within about 35 days of a new job starting, and the correction comes through automatically in a later payslip.

K codes: when the number goes negative

A K code is the one that alarms people, and it is worth understanding because more teachers will meet it as the Child Benefit charge coding-out route becomes standard. GOV.UK defines it as meaning "you have income that you are not paying tax on which is more than your Personal Allowance".

Mechanically, the deductions HMRC needs to make have exceeded your allowance, so instead of a tax-free amount you have a notional extra amount of income added to your pay for tax purposes. The K sits at the front of the code rather than the end — K475, not 475K — which is the quickest way to recognise one. There is a safeguard in the PAYE regulations, known as the overriding or 50% regulatory limit: the tax deducted in any pay period cannot exceed half of your gross pay for that period. Anything above that is carried forward rather than taken.

The realistic routes into a K code for a teacher are a High Income Child Benefit Charge being collected through PAYE, a significant underpayment from an earlier year being recovered, or a large taxable benefit-in-kind — for example a car provided through an EV salary sacrifice scheme, which carries a taxable benefit charge of 4% of list price in 2026/27. A K code is not a penalty and not a sign you have done anything wrong; it is arithmetic.

What is, and is not, in a teacher's tax code

Here is the one genuinely teacher-specific point on this page, and it surprises people. Your Teachers' Pension contribution does not appear in your tax code at all, and it never will.

The TPS operates a net pay arrangement: your employer deducts your contribution from your pay before calculating income tax on the remainder. The relief is therefore given by payroll, automatically, at your marginal rate, with nothing for HMRC to code. A tax code adjustment is the mechanism used for relief-at-source pension schemes, which the TPS is not.

The practical consequence is that a teacher's tax code usually looks entirely unremarkable even though their pension contribution is doing more to reduce their tax bill than anything in the code. It is also why the salary figure that governs your tax band is gross pay minus your pension contribution — the reason a teacher does not become a 40% taxpayer until roughly £55,790 of gross salary rather than £50,270.

• Appears in your code: union and professional subscription relief, once HMRC has accepted a claim.
• Appears in your code: taxable benefits-in-kind — private medical cover, a company car, an EV salary sacrifice vehicle.
• Appears in your code: tax underpaid in an earlier year being recovered, and small Self Assessment bills coded out.
• Appears in your code: the High Income Child Benefit Charge, if you use HMRC's PAYE route for it.
• Appears in your code: Marriage Allowance, in either direction.

• Never appears in your code: your Teachers' Pension contribution, at any tier.
• Never appears in your code: TPS faster accrual, buy-out or additional pension contributions — all deducted under the same net pay mechanism.
• Never appears in your code: your student loan repayment, which payroll calculates separately from your gross pay.
• Never appears in your code: National Insurance, which is worked out on gross pay per pay period and has no code at all.

Find your situation

Almost every tax code question a teacher asks is really a question about one of these five situations. Each has a page on this site that answers it properly rather than in passing.

How to check and fix a wrong code

Your code appears on your payslip, on the P2 coding notice HMRC sends when it changes, and in your Personal Tax Account or the HMRC app, which is the fastest place to look. The Personal Tax Account also shows the breakdown — what has been added, what has been deducted, and the estimated income HMRC has assumed for the year, which is often where an error originates.

• Check the estimated annual income HMRC is using for your teaching post. A stale figure from before a promotion, a TLR or a pay award is the single most common cause of a wrong code.
• Check that any benefit-in-kind deduction matches what you actually receive.
• Check that a BR or D0 code is on your second income and not your main teaching post.
• Check that you are not still on a W1/M1/X code months after starting — chase payroll for your P45 or starter checklist if you are.
• If you have moved to or from Scotland, check the S prefix. HMRC uses your home address, and it does not always update itself.
• Correct it through your Personal Tax Account or the HMRC app, which is faster than the helpline. Your school's payroll cannot change your code — only HMRC can issue one.

If a wrong code has cost you money, the correction is usually automatic once the right code is issued: a cumulative code recalculates the whole year to date at the next payday and refunds the difference through your pay. If the tax year has already ended, HMRC reconciles it after the year end and issues a P800 calculation. Either way it is worth fixing promptly rather than waiting, because an underpayment left to run gets collected through a lower code the following year.