Guides · UK tax codes
UK tax codes explained
How UK tax codes work
A UK tax code has two parts:
- A numeric prefix that represents the amount of tax-free income per year, divided by 10. So 1257 means £12,570, 1000 means £10,000, 0 means £0.
- A letter suffix that modifies how the employer applies the number. L is the standard "Personal Allowance" code.
The employer uses the code to set the tax-free portion of each pay period (annual amount / 12 for monthly, / 52 for weekly, / 13 for four-weekly, / 26 for fortnightly) and applies the brackets to the remainder.
For 2026/27, the standard Personal Allowance is £12,570, so the standard tax code is 1257L. Each year HMRC indexes allowances to inflation; the code's numeric prefix changes accordingly.
Standard codes (1257L and friends)
| Code | Meaning | Effect on tax |
|---|---|---|
| 1257L | Standard Personal Allowance (£12,570) | First £12,570 of income is tax-free; rest per bands |
| 1257L (cumulative) | Same as 1257L but calculated year-to-date | Standard treatment — used in non-cumulative mode if employer requests |
| 1185L | Marriage Allowance transfer received (basic-rate only) | £1,260 of spouse's Personal Allowance transferred to you |
| 1200L | Personal Allowance adjusted for underpayment collection | Reduced by HMRC to recover a prior year's underpayment |
| 1290L | Personal Allowance adjusted (underpayment collected) | Same — number varies with adjustment |
The "L" suffix simply means "Personal Allowance." Most employees will see one of the L codes. HMRC occasionally reduces the numeric prefix to collect an underpayment from a prior year (a "coding adjustment"). The maximum reduction is 50% of the Personal Allowance.
Emergency codes (BR, 0T)
| Code | Meaning | Effect on tax |
|---|---|---|
| BR | Basic Rate — all income taxed at 20% | No Personal Allowance; basic rate applies to every pound |
| 0T | No Personal Allowance, all income per bands | Same as a non-allowance scenario — 20% on first £37,700, 40% above, etc. |
| BR (second job) | Often the default for a second employment | All income from that employment at basic rate |
BR is the most common non-standard code. It applies when:
- You take on a second job and the new employer hasn't completed the HMRC new-starter checklist — BR becomes the default.
- You have income from a state pension or workplace pension that HMRC wants to tax at source (with no allowance, because you've used the Personal Allowance on your main job).
- Your main employer's tax code is non-standard and HMRC wants to isolate the second income.
BR at 20% on every pound means you're paying basic rate on income that would otherwise be tax-free up to £12,570. If your second job pays £5,000/year, you overpay ~£1,000 of tax — HMRC refunds via your Personal Tax Account after year-end.
0T is similar but lets the bands apply — the first £37,700 of income from that source is at 20%, the next slice at 40%, etc. Less common than BR but appears when HMRC loses your code or doesn't have one on file.
K codes — negative allowances
A K code is the opposite of an L code: it represents an amount to be added to your taxable income, not subtracted. K codes look like K100, K500, K1500, etc. — the number × 10 is the additional taxable amount.
Common triggers:
- Receiving more than £12,570 of state pension and having no other income to absorb the allowance — HMRC claws it back via a K code on the state pension.
- Outstanding underpayment from a prior year that's too large to recover via a reduced L code (more than 50% of the Personal Allowance).
- Receiving taxable benefits in kind that you haven't paid tax on (e.g., a benefit that should have been taxed under PAYE but wasn't).
K codes produce higher withholding than L codes. A K1000 code on £40,000 of income adds £10,000 to taxable pay — your employer withholds more, and the year-end reconciliation should net out close to zero.
D codes — higher-rate only
D codes are used when the Personal Allowance has been fully used by another source of income, and the remaining income is taxed at higher or additional rate only:
| Code | Rate applied |
|---|---|
| D0 | 40% (higher rate) on all income |
| D1 | 45% (additional rate) on all income |
These typically appear on employment income where the employee has already used their Personal Allowance on a pension or another job, and HMRC wants the rest at the higher rate without further tapering.
Other codes (NT, S, C)
| Code | Meaning |
|---|---|
| NT | No tax to be withheld. Used for non-taxable employment (e.g., some categories of armed forces pay). |
| S | Scottish tax code (the Personal Allowance is the same, but bands are different). |
| C | Welsh tax code (Welsh rates of income tax — Welsh parliament sets the rates, but the Personal Allowance remains UK-wide). |
Scottish rates differ from the rest of the UK — Scotland has five bands (19%, 20%, 21%, 42%, 47% in 2026/27, including a starter rate of 19%). An S code signals that Scottish bands apply; the Personal Allowance numeric prefix is still £12,570 for the basic 1257S.
Welsh rates are an additional rate on top of UK rates — 10p in the pound (10%) for basic, 14p higher, 19p additional. The C code applies Welsh rates; the Personal Allowance is still £12,570.
National Insurance category letters
Separate from the income-tax code is the NI category letter, which determines the rate of employee National Insurance. Most employees are category A.
| Category | Who it's for |
|---|---|
| A | Standard employee (most common) |
| B | Married women/widows entitled to reduced NI (legacy — rare now) |
| C | Employees over state pension age (no NI) |
| F | Married women entitled to reduced NI (legacy) |
| H | Apprentices under 25 (NI-free up to upper earnings limit) |
| J | Employees eligible to defer NI (deferral elections) |
| M | Employees under 21 (NI-free up to upper earnings limit) |
| V | Married women entitled to reduced NI (legacy) |
| Z | Employees under 21, deferral in place (rare) |
Category H (apprentices under 25) and M (under 21) entitle the employee to zero NI on earnings up to the upper earnings limit (£50,270 in 2026/27). Above that, the standard 2% rate applies. This is a real benefit for young workers and apprentices — but only until they hit state pension age or leave the qualifying scheme.
How to check your code
Three places to find your current code:
- Your payslip — usually shown next to "Tax Code" with the weekly or monthly multiplier.
- Your P60 (issued 31 May for the prior tax year).
- Your Personal Tax Account on GOV.UK — the most current view.
If your code looks wrong, contact HMRC via the Personal Tax Account or by phone. Changes typically take effect in the next pay period.
Common reasons to query your code:
- You've changed jobs and your old employer's code is still on file.
- You're on emergency tax (BR or 0T) longer than expected.
- You're underwithholding or overwithholding by a significant amount each month.
- You've started receiving a state pension and your tax code has changed.
- You have benefits in kind (e.g., company car, medical insurance) that should affect your code.