National Insurance contributions (NICs) are a tax on earnings and self-employment profits that fund the State Pension, certain benefits, and the NHS. Unlike income tax, which goes into the general pot, NICs have a more direct link to what you get back — particularly your State Pension entitlement. But the system is genuinely complicated, with different classes depending on how you earn your money.
Class 1 — employees
If you're employed, you pay Class 1 NICs on earnings above the primary threshold. The current rates are:
- £12,570 to £50,270 — 8%
- Over £50,270 — 2%
Your employer also pays Class 1 NICs at 15% on your earnings above £5,000 (the secondary threshold). This employer contribution doesn't come out of your pay, but it's a real cost of employing you — and it's one reason why employers sometimes prefer contractors.
The 8% rate was reduced from 10% in January 2024, which put a few extra pounds in most people's pockets. Whether that offset the effects of frozen tax thresholds is debatable.
Class 2 and Class 4 — self-employed
If you're self-employed with profits above £12,570, you pay Class 4 NICs:
- £12,570 to £50,270 — 6%
- Over £50,270 — 2%
Class 2 NICs (£3.45 per week) were effectively abolished in April 2024 for most self-employed people, though voluntary contributions remain available for those who want to protect their State Pension record.
Class 3 — voluntary contributions
If you have gaps in your National Insurance record — perhaps because you were abroad, not working, or caring for someone — you can make voluntary Class 3 contributions to fill them. The current rate is £17.45 per week. This can be extremely good value if it secures you additional years towards the full State Pension.
You can check your NI record through your Personal Tax Account on GOV.UK to see if you have any gaps worth filling. The government recently extended the deadline for buying back years going back to 2006, so it's worth checking before that window closes.
How NICs affect your State Pension
You need 35 qualifying years of NICs to get the full new State Pension (currently £221.20 per week). A minimum of 10 years gives you a partial pension. Qualifying years can come from employment, self-employment, National Insurance credits (if you're claiming certain benefits or caring for a child under 12), or voluntary contributions.
For many people, especially women who took career breaks for childcare, checking your NI record and considering voluntary contributions could be one of the best financial decisions you make. Paying £900 to buy a missing year could increase your annual State Pension by around £330 — that's a payback period of under three years.
National Insurance and your payslip
On your payslip, you'll see NI deducted alongside income tax and pension contributions. Your NI number (formatted like QQ 12 34 56 A) is unique to you and stays with you for life. If you don't know yours, you can find it on previous payslips, your P60, or by requesting it through GOV.UK.
When do you stop paying?
You stop paying employee NICs when you reach State Pension age, even if you continue working. However, your employer still pays their share. Self-employed people also stop paying Class 4 NICs at State Pension age, though they may still want to file a self assessment return for income tax purposes.