Payslip Auditor

A payslip shows your gross pay, then deductions: Income Tax (PAYE), National Insurance, pension and any student loan, leaving your net pay. It also shows your tax code and often year-to-date totals. Checking these each month takes seconds and catches errors early, while they're easy to fix.

The standard 2025/26 code is 1257L, meaning a £12,570 tax-free allowance. The number is your allowance ÷ 10; the letter reflects your situation. Watch for emergency codes like W1, M1 or X (which tax each period in isolation and often over-deduct), BR (all income taxed at basic rate, common on a second job), or 0T/K codes. A wrong code is the single most common reason for paying too much or too little.

PAYE is normally cumulative: it spreads your allowance and bands evenly across the year and self-corrects each payday. So a single odd month (a bonus, a pay rise, a new job) can look wrong but balance out. An emergency (non-cumulative) code doesn't do this, which is why it often over-taxes until corrected.

If you've overpaid, HMRC usually refunds it automatically through your pay once your code is corrected, or after the tax year via a P800. To fix a wrong code, contact HMRC or update your details in your Personal Tax Account. You can reclaim overpaid tax for up to four previous years. Keep your payslips and P60s as evidence.

• Never checking the tax code. A wrong code can over-tax you for months. Check it against 1257L and your circumstances.
• Ignoring emergency tax. W1/M1/X codes over-deduct. Get your code corrected to recover it sooner.
• Not claiming a refund. Overpaid tax can be reclaimed for up to four years, don't leave it.
• Assuming a second-job BR code is wrong. BR is normal for a second job, but check your allowance is applied to your main job.