Your HMRC tax code is the short string — usually something like 1257L — that tells your employer or pension provider how much Income Tax to take out of each payslip under PAYE. Get it right and the tax deducted across the year lines up with what you actually owe. Get it wrong and you quietly overpay for months, or end up with a nasty year-end bill.
This guide walks through what every letter and number means for the 2026-27 tax year, how to check yours, and exactly what to do if it looks wrong. For a quick machine-readable decode of your specific code, use the free HMRC Tax Code Checker — it handles all the variants covered below.
What a Tax Code Actually Does
HMRC issues your tax code and sends it to your employer via a P6 / P9 notice. You see it on the P2 “coding notice” that HMRC posts or shows in your Personal Tax Account. Your employer then uses the code — not your actual circumstances — to calculate how much tax to withhold each payday.
The code is a shorthand for two things:
- Your tax-free Personal Allowance — how much you can earn in a year before any Income Tax is due.
- Any special rule HMRC wants applied, such as “tax all income at basic rate” or “this is the Scottish rate”.
Because employers only see the code (not the full reasoning), an out-of-date code silently misapplies tax until someone spots it.
Anatomy of a UK Tax Code
A standard code has a number followed by a letter. The number is your Personal Allowance divided by 10. The letter tells your employer which rule set applies.
- 1257L → Personal Allowance of £12,570 × 1 = £12,570 tax-free, standard rules
- 1383L → £13,830 tax-free (higher than standard — e.g. Marriage Allowance received plus another adjustment)
- 1185L → £11,850 tax-free (lower than standard — small benefit-in-kind or unpaid tax being collected)
- K475 → negative allowance of −£4,750 (extra income added to taxable pay rather than sheltered)
Some codes have no number at all — BR, D0, D1, NT, 0T — because the rule doesn’t depend on an allowance. And some have a prefix (S for Scottish, C for Welsh) or a non-cumulative suffix (W1, M1, X) that changes the calculation basis.
Common UK Tax Codes in 2026-27
The Personal Allowance has been frozen at £12,570 since 2021-22 and remains frozen through at least 2027-28, so 1257L is the default code for nearly everyone with a single, straightforward job in 2026-27.
Here are the codes you are most likely to encounter, with plain-English meanings and links to deeper explanations and worked examples.
1257L — The Standard Code
If you have one employment, no company car, no taxable benefits-in-kind, no state pension, and HMRC has up-to-date information, you are on 1257L. It gives you the full £12,570 Personal Allowance, taxed cumulatively across the year so that by week 52 / month 12 the right total has been withheld.
See the dedicated Tax Code 1257L explainer for worked examples at £20k / £50k / £80k / £100k.
BR — Basic Rate on All Income
BR strips away the Personal Allowance and taxes every pound at the 20% basic rate. It’s almost always applied to a second income source — a second job, a private pension alongside employment, or an occupational pension alongside the State Pension — because HMRC assumes your main job is already using up the full £12,570 allowance.
If BR is on your only job, something is wrong. You’re missing out on £12,570 × 20% = £2,514 per year of tax-free pay. Full BR tax code guide.
D0 — Higher Rate on All Income
D0 taxes the source at a flat 40% with no allowance and no basic-rate band. It’s used for a second income when your main job already tips you into the higher-rate band (earning above £50,270 from your primary employment). Scottish equivalent: SD0 taxes the source at 21% (Scottish intermediate rate). D0 worked examples.
D1 — Additional Rate on All Income
D1 applies the 45% additional rate to every pound, with no allowance. Typically used when your main job already lands you in additional-rate territory (over £125,140 for rUK, over £125,140 for Scotland where the top rate is 48%). Scottish equivalent: SD1 is 42% (Scottish higher rate), SD2 is 45% (Scottish advanced rate). D1 worked examples.
0T — No Personal Allowance
0T is not quite the same as BR. It removes the Personal Allowance but then applies the normal rate bands — so income is taxed at 20%, then 40%, then 45% as it crosses thresholds. You’ll see 0T most often as the emergency default for a new starter without a P45 and no completed Starter Checklist: HMRC has no information, so it taxes you progressively but without any tax-free amount. 0T detail and scenarios.
NT — No Tax at Source
NT means no tax is deducted at all. It’s rare and specific — valid cases include non-UK tax residents covered by a double-taxation treaty, seafarers under the Seafarers’ Earnings Deduction, and certain overseas pension arrangements. If you’re a UK-resident employee and see NT, contact HMRC immediately — it is almost always wrong. NT background.
K Codes — Negative Allowance
A K code is what HMRC uses when the untaxed income they need to collect through PAYE exceeds your Personal Allowance. Instead of sheltering £12,570, the code adds a notional amount to your taxable pay.
- K100 adds £1,000 to your annual taxable income — roughly £200/year extra tax at basic rate
- K500 adds £5,000 — common for a mid-value company car
- K1000 adds £10,000 — typical when State Pension + company car together outstrip the allowance
K codes are capped so no single pay period can have more than 50% of gross pay taken in tax. Full K code library | K200 | K500 | K1000.
If you’re on a K code and don’t think you should be, check your P2 coding notice — it breaks down exactly which benefits or arrears HMRC is collecting.
M and N — Marriage Allowance
Marriage Allowance lets a non-taxpaying spouse transfer 10% of their Personal Allowance (£1,260) to a basic-rate-paying partner, saving up to £252/year in tax.
- M suffix (e.g. 1383M, 1282M) — you are the recipient, your allowance is topped up by £1,260
- N suffix (e.g. 1131N) — you are the transferor, your allowance is reduced by £1,260
Only the lower earner’s spouse can transfer; both must be born on or after 6 April 1935. 1282M explainer | 1131N explainer.
W1, M1, X — Emergency (Non-Cumulative) Codes
Any code with W1, M1, or X after it (e.g. 1257L W1, 1257L M1) is non-cumulative. Each pay period is taxed in isolation as if it were 1/52 or 1/12 of the year, rather than using year-to-date totals.
You’ll typically see this when:
- You start a new job without handing over a P45
- You fill in a Starter Checklist but HMRC hasn’t yet sent your full code
- Your employer doesn’t yet have an accurate figure for the year
Emergency codes usually overpay tax because they can’t account for lower-paid weeks earlier in the year. The overpayment is refunded automatically once HMRC issues your proper cumulative code, but it can take several pay periods. 1257L W1 (weekly) | 1257L M1 (monthly).
S Prefix — Scottish Taxpayer
If your main home is in Scotland, HMRC classifies you as a Scottish taxpayer and prefixes your code with S — for example, S1257L. The number still means the same £12,570 allowance, but Scottish Income Tax bands apply to earnings above it.
Scottish bands for 2026-27 (indicative — always confirm current rates on gov.scot):
- Starter rate 19% on the next ~£2,306 above the allowance
- Basic rate 20% up to ~£27,491
- Intermediate rate 21% up to ~£43,662
- Higher rate 42% up to £75,000
- Advanced rate 45% up to £125,140
- Top rate 48% above £125,140
S-prefix variants: S1257L, SBR, SD0 (21%), SD1 (42%), SD2 (45%). See Scotland vs Rest-of-UK tax comparison for the full side-by-side.
C Prefix — Welsh Taxpayer
Welsh taxpayers see a C prefix (for example C1257L). Although the Welsh government has the power to set its own rates, since the Welsh Rates of Income Tax were introduced in 2019, Wales has kept rates aligned with England and Northern Ireland — so in practice your take-home on a C-prefix code matches that of an unprefixed code. C1257L detail.
T Suffix — HMRC Is Reviewing
A T suffix (e.g. 580T) means HMRC has applied a non-standard allowance and wants it reviewed periodically — common for the Personal Allowance taper (income £100,000–£125,140), for split allowances between jobs, or for specific one-off adjustments. The number is still your allowance ÷ 10. 580T worked example.
Summary Table: Every Code at a Glance
| Code | What it means | Typical use |
|---|---|---|
| 1257L | Full £12,570 allowance, standard rules | Most single-job employees |
| Other L (e.g. 1185L, 1383L) | Adjusted allowance + L rules | Small BIK, unpaid tax, or MA combined |
| M | Marriage Allowance received | Recipient of £1,260 transfer |
| N | Marriage Allowance transferred | Transferor of £1,260 |
| T | Allowance needs HMRC review | PA taper, split allowances |
| K | Negative allowance | BIK / State Pension / arrears exceed PA |
| BR | 20% flat, no allowance | Second job or pension |
| D0 | 40% flat, no allowance | Second income when main job is higher-rate |
| D1 | 45% flat, no allowance | Second income when main is additional-rate |
| 0T | No allowance, normal bands | New starter without P45 |
| NT | No tax deducted | Non-residents, specific treaty cases |
| S prefix | Scottish rates apply | Scottish taxpayer |
| C prefix | Welsh rates apply | Welsh taxpayer |
| W1 / M1 / X | Non-cumulative (emergency) | Missing P45, HMRC updating |
How to Check Your Own Tax Code
Your code appears in several places. Cross-check at least two:
- Your latest payslip — top corner, usually labelled “Tax code” or “T/C”.
- Your P60 — issued by your employer by 31 May each year, shows the code at year-end.
- Your P45 — given when you leave a job, shows the code your previous employer was using.
- Your P2 coding notice — HMRC posts this when they change your code; it breaks down exactly what’s included.
- HMRC Personal Tax Account — log in at gov.uk/personal-tax-account or via the HMRC app to see your current code and how HMRC calculated it.
- HMRC Tax Code Checker — paste the code in to decode letters, prefix, and get an estimated tax figure on 2026-27 rates.
If you have two or more jobs / pensions, check the code on each one separately — they should not all be 1257L.
How to Fix a Wrong Tax Code
Errors are common after a job change, a pay rise that crosses a threshold, a new company car, or HMRC holding an outdated estimate of your other income.
- Gather evidence: payslip, P2 coding notice (if received), details of any company benefits, and — if you have a second job — payslips from that too.
- Use the HMRC Tax Code Checker to confirm whether the code is plausible for your circumstances.
- Update HMRC online: via your Personal Tax Account or the HMRC app, you can correct your estimated income, remove a benefit you no longer receive, or claim Marriage Allowance.
- Call HMRC on 0300 200 3300 (PAYE helpline) if the online tool can’t fix it. Have your National Insurance number and UTR (if self-employed) to hand.
- Wait for the corrected code: HMRC issues a new P6 / P9 to your employer, usually within 5–10 working days. The employer applies it on the next payroll run.
- Overpayments refund automatically through the remaining paydays of the same tax year. If the overpayment was from a previous year, HMRC issues a P800 tax calculation letter after year-end.
Don’t wait until Self Assessment (31 January) to fix a wrong code — that just delays the refund by months.
Scottish vs Rest-of-UK: Why the Prefix Matters
Scotland sets its own Income Tax rates and bands (it has done since 2017-18), and the S prefix tells your employer to use them. The Personal Allowance itself (£12,570) is set UK-wide by HM Treasury, so it’s the same in Scotland, England, Wales and Northern Ireland — but what happens above the allowance diverges:
- rUK (England/Wales/NI): three bands (20% / 40% / 45%)
- Scotland: six bands (19% / 20% / 21% / 42% / 45% / 48%)
HMRC classifies you as a Scottish taxpayer based on where your main home was for the majority of the tax year. Moving mid-year can change your status for the following year. If you see an unexpected S prefix — or an unexpected removal of one — update your address in your Personal Tax Account first, then check whether HMRC agrees with your Scottish status.
See the full England vs Scotland tax comparison and the interactive England vs Scotland comparison tool for worked side-by-side take-home figures.
Frequently Asked Questions
What is the standard UK tax code for 2026-27?
1257L is the standard code. It reflects the Personal Allowance of £12,570, which has been frozen since 2021-22 and remains frozen through 2027-28. Most employees with a single job and no taxable benefits are on 1257L.
Why do I have two different tax codes?
If you have two jobs or a job plus a pension, each source needs its own code. Typically your main job gets 1257L and your second source gets BR, D0 or D1 depending on your total income. That way your full £12,570 allowance is used exactly once, against your largest income.
What happens if I’m on an emergency tax code (W1/M1/X)?
You’ll probably overpay tax short-term because each pay period is taxed in isolation without accounting for year-to-date earnings. Once HMRC issues your proper cumulative code, any overpayment is automatically refunded through the remaining pay periods of the tax year. Handing in a P45 or completing a Starter Checklist speeds this up.
Will my tax code change when the new tax year starts?
HMRC reviews and reissues codes each February–March for the new tax year starting 6 April. If your Personal Allowance is unchanged (it is for 2026-27 — still £12,570) and your circumstances haven’t changed, your code will stay the same. If you have a new company car, a pay change affecting your band, or new taxable benefits, expect a revised code.
How do I get the Personal Allowance increased on my tax code?
Most reasons to increase the allowance are automatic: Marriage Allowance transfer, employment expenses claimed through HMRC, or professional subscriptions. To actively claim any of these, use your Personal Tax Account and submit the relevant claim. HMRC reissues the code within a few weeks.
Does my tax code affect National Insurance?
No. National Insurance is calculated separately, per pay period, based on your NI category letter (A, M, H, etc.) and the Primary Threshold / Upper Earnings Limit. Your tax code only drives Income Tax. See How National Insurance is calculated for the parallel rules.
What if I’m self-employed — do I have a tax code?
If you are purely self-employed with no employment or pension income, you don’t have a tax code — you settle your Income Tax through Self Assessment instead. If you have both employment and self-employment, your employment has a tax code (usually 1257L) and your self-employed profits are taxed via Self Assessment on top.
Related Tools and Guides
- HMRC Tax Code Checker — decode any code and see your estimated tax
- Income Tax Calculator — full bracket-by-bracket breakdown for 2026-27
- Take-Home Pay Calculator — full PAYE + NI + student loan take-home
- Marriage Allowance Calculator — see if M/N codes are worth claiming
- England vs Scotland Tax Comparison — S-prefix vs non-S, side-by-side
- Personal Allowance Taper Explained — why high earners see unusual T codes
- HMRC Personal Tax Account Guide — how to check and fix your code online
Sources
- GOV.UK — Tax codes (primary reference)
- GOV.UK — Check your Income Tax for the current year
- GOV.UK — Income Tax rates and Personal Allowances
- GOV.UK — Marriage Allowance
- GOV.UK — Personal tax account: sign in or set up
- gov.scot — Income Tax in Scotland
- HMRC PAYE Manual PAYE11000 (Coding: codes — use of)