Class 1 National Insurance

Definition

Class 1 NI is paid by employees on their earnings above a certain threshold. For 2026/27, category A employees generally pay 8% on earnings between the primary threshold and the upper earnings limit, then 2% above the upper limit. Your employer also pays secondary Class 1 NI above the applicable secondary threshold. Rates depend on category and pay period, and NI records affect entitlement to some benefits and the State Pension.

Why it matters

• It is the most common type of NI — most employees pay it automatically through PAYE.
• Unlike Income Tax, the way NI is calculated (per pay period, not annual) can create timing effects.

Common use cases

• Payslip deduction understanding
• Comparing gross vs net pay
• Checking State Pension record