National Insurance2026/27

What is Class 1 National Insurance? UK Definition 2026/27

Verified by ICAEW, ACCA & AAT
Updated April 2026

Quick Answer

NI paid by employees (8%/2%) and employers (15%) on employment earnings.

Definition of Class 1 National Insurance

Class 1 National Insurance is paid on employment earnings. Employee contributions are 8% on earnings between £12,570 and £50,270, then 2% above. Employers pay 15% on all earnings above £5,000. Class 1 NI builds entitlement to State Pension and contributory benefits like JSA and ESA.

Class 1 National Insurance — Key Facts for 2026/27

Employee rate8% / 2%
Employer rate15%
Primary threshold£12,570/year
Secondary threshold£5,000/year

How Class 1 National Insurance Works — Example

Class 1 NI on £50,000 salary
  1. 1Employee NI: (£50,000 - £12,570) x 8% = £2,994
  2. 2Employer NI: (£50,000 - £5,000) x 15% = £6,750
  3. 3Total NI: £9,744
  4. 4Employer cost of employment: £56,750

How Class 1 National Insurance Affects Your Tax

Class 1 NI is a significant cost for both employees and employers. Its in addition to income tax, making the true marginal rate on employment income 28% or 42% (including employee NI only).

Official HMRC Guidance on Class 1 National Insurance

For official guidance, refer to HMRC's documentation. Tax rules can change, so always verify current rates and thresholds on gov.uk.

HMRC: National Insurance

Frequently Asked Questions about Class 1 National Insurance

Accuracy Note

This information is for guidance only and is based on 2026/27 tax year rates. Tax rules are complex and your circumstances may differ. For personal advice, consult a qualified accountant or tax adviser.