How UK PAYE Works: A Complete Guide for Employees 2026/27
Updated: March 2026 | 2026/27 Tax Year
PAYE — Pay As You Earn — is the system HMRC uses to collect income tax and National Insurance automatically from your wages before you ever see them. It's been running since 1944, and yet most employees have no idea how it actually works. This guide changes that.
What Is PAYE?
PAYE is simply a collection mechanism. Instead of you paying your own tax bill once a year, your employer calculates and deducts the right amount from every payslip and sends it to HMRC on your behalf. The same system handles National Insurance contributions for both you and your employer.
Over 34 million workers in the UK are paid via PAYE. It covers employees in full-time, part-time, temporary, and zero-hours roles. Only the self-employed fall outside PAYE — they report income via Self Assessment instead.
Quick PAYE Estimator
Drag to see your estimated PAYE deductions. For a full breakdown, use our salary calculator.
£4,486
Income Tax
£1,794
National Insurance
£28,720
Annual Take-Home
£2,393
Monthly Take-Home
How Does PAYE Calculate Your Tax?
Your employer receives a tax code from HMRC for each employee. This code tells the payroll system how much tax-free income you're entitled to per pay period. The calculation each payday is:
- 1Start with your gross pay (salary + any bonus)
- 2Subtract any pension contributions made via salary sacrifice
- 3Work out your tax-free allowance for this pay period (annual allowance ÷ 12 for monthly)
- 4Subtract the allowance → this is your taxable pay
- 5Apply the tax rates: 20% basic, 40% higher, 45% additional
- 6Deduct the result from gross pay, along with NI
Where Does Your Gross Pay Go?
Breakdown across 7 salary levels — income tax, NI, and take-home. 2026/27 rates.
England, Wales & NI rates. Excludes pension/student loan.
£50,000 Salary — How It Splits
Understanding Your Tax Code
The most common code for 2026/27 is 1257L. Here's how to read it:
| Part | Meaning | Example |
|---|---|---|
| Number (1257) | Your tax-free allowance ÷ 10 | 1257 × 10 = £12,570 allowance |
| L | Standard Personal Allowance | Entitled to the full £12,570 |
| M or N | Marriage Allowance transfer | M = received, N = transferred |
| BR | Taxed at 20% on all income | Second job with no allowance |
| D0 | Taxed at 40% on all income | Second job, higher rate earner |
| K | Negative allowance | Normally for benefits in kind |
| W1/M1 | Non-cumulative (week/month 1 basis) | Only current period is assessed |
Cumulative vs Week 1/Month 1
By default PAYE is cumulative — it looks at your total income from 6 April to date each time it calculates tax. This means if you earned less earlier in the year, PAYE may deduct less tax now to catch up. This is actually the reason why January and February payslips sometimes show a slightly different net pay.
If your code has W1 (week 1) or M1 (month 1) at the end, it runs in non-cumulative mode — only looking at the current period. This is often used when HMRC issues an emergency code mid-year.
What If HMRC Gets It Wrong?
Tax codes are automatically generated by HMRC based on P60s, P45s, and information employers report in real-time. But they're not infallible. Common errors include:
- Using last year's benefits in kind figure when it's changed
- Not accounting for a pay rise or new role
- Applying an incorrect emergency code after a job change
- Missing pension contributions that should reduce your taxable income
If your code is wrong, contact HMRC via the Government Gateway or call 0300 200 3300. You can also update your details online. Any overpaid tax will be refunded, usually via a P800 notice after the tax year ends.
PAYE vs Self Assessment
If you earn over £100,000, have significant investment income, or are self-employed with some PAYE income on the side, you may need to file a Self Assessment return in addition to being on PAYE. PAYE doesn't handle the Personal Allowance taper at £100k well — it typically requires manual correction via SA.
Check Your Own PAYE Calculation
Use our UK Salary Calculator to verify your expected take-home. Enter your tax code, and the calculator will replicate the PAYE logic exactly. If your payslip differs, check our guide: Why Your Payslip Differs from Online Calculators.