UK / Pillar
National Insurance
Class 1 National Insurance is deducted from earnings above the Primary Threshold each pay period. For 2026/27 the main employee rate is 8% from the Primary Threshold up to the Upper Earnings Limit, then 2% above.
Educational guidance only. Not affiliated with HMRC. Not regulated tax, legal, financial, payroll or employment advice.
Common NI category letters
- A — most employees, full rate.
- B — married women / widows on reduced rate (legacy, rare).
- C — over State Pension age (no employee NI).
- H — apprentice under 25.
- J — deferring NI because of another employment.
- M — under 21.
- V — veteran in first 12 months of civilian employment.
- X — under 16 (no NI).
- Z — under 21 deferring.
Quick answer — why does my NI look wrong?
Most NI surprises come from the wrong category letter, salary sacrifice not lowering NIable pay correctly, or a one-off bonus crossing the Upper Earnings Limit.
Related
Educational guidance only. PayslipIQ provides an educational second opinion based on the figures you supply and the public 2026/27 UK PAYE, NI, pension and student-loan rules. Verify any final figure with your payroll team, HMRC, your pension provider or a qualified professional before acting.
See our methodology, Trust Centre and AI limitations.