National Insurance Calculator
Calculate UK National Insurance for employees (Class 1) and the self-employed (Class 4) for the 2025/26 tax year.
Your income
NI on a Self Assessment return?
Class 4 NI for the self-employed is calculated and filed by us as part of your annual Self Assessment from £79.
What is National Insurance?
National Insurance (NI) is a tax on earnings that funds state pension, NHS contributions, statutory sick pay, maternity allowance and unemployment benefits. You build qualifying years (for state pension) by paying enough NI in any given year — 35 qualifying years gets you the full new state pension.
There are several "classes":
- Class 1 — employees (paid via PAYE) and employers
- Class 2 — self-employed flat-rate (now voluntary from April 2024)
- Class 3 — voluntary, fills gaps in your record
- Class 4 — self-employed profit-based (paid via Self Assessment)
NI rates 2025/26
| Class | Threshold | Main rate | Above £50,270 |
|---|---|---|---|
| Class 1 employee | £12,570 | 8% | 2% |
| Class 1 employer | £5,000 (Apr 2025) | 15% | 15% |
| Class 2 self-employed | £6,725 (voluntary) | £3.45/wk | — |
| Class 4 self-employed | £12,570 | 6% | 2% |
Class 2 became voluntary from April 2024 — you don't need to pay it, but you still get a qualifying year if your profits exceed the threshold.
When do you pay NI?
Class 1 is deducted automatically each pay run via PAYE — you don't do anything. Class 4 is calculated and paid as part of Self Assessment, due 31 January.
If you have gaps in your NI record, you can pay Class 3 voluntary contributions to fill them — currently £17.45/week. Worth checking your record at gov.uk/check-state-pension before paying.
Reduce NI legitimately
- Salary-sacrifice schemes (pension, cycle-to-work) reduce gross before NI is calculated
- Going Ltd — director's salary at NI threshold + dividends can save 8–13% NI on the dividend portion
- Tronc schemes (hospitality) — tips through tronc are NI-free for both employee and employer
- Spread income across spouses if running a partnership
What this calculator does and doesn't do
- Class 1 employee NI: 8% on £12,570–£50,270, 2% above
- Class 4 self-employed NI: 6% on £12,570–£50,270, 2% above
- Class 2 NI (£3.45/week) is voluntary from April 2024 — not included
- Doesn't include employer Class 1 (13.8%, rising to 15% from April 2025) — that's a cost to the employer, not the employee
If you found this useful
Stop dreading tax. Start ignoring it.
Get a fixed-fee quote in 60 seconds. No signup, no card, no sales call. We'll just tell you what it'll cost and how fast we can file it.