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What is UK National Insurance?

National Insurance (NI) is a UK social-security tax paid by employees, employers, and the self-employed that funds the state pension, contributory benefits, and the NHS. For 2026/27 employees pay 8 percent on earnings GBP 12,570 to GBP 50,270 and 2 percent above.

Detailed definition

National Insurance was created by the National Insurance Act 1911 (Lloyd George's "ninepence for fourpence" scheme covering health and unemployment) and rebuilt comprehensively by Clement Attlee's 1946 National Insurance Act, which extended cover to the state pension, sickness, unemployment, and bereavement benefits. The contribution-record-to-benefit link is the core constitutional feature, distinguishing NI from general income tax even though both are administered by HMRC and feel similar from a payslip.

NI is divided into classes by the type of contributor. Class 1 is paid by employees (the Primary contribution) and their employers (the Secondary contribution). Class 2 was a flat-rate self-employed levy abolished as mandatory from April 2024 (still available voluntarily). Class 3 is voluntary and used to fill gaps in a contribution record. Class 4 is paid by the self-employed on annual profits.

NI receipts go into the National Insurance Fund, ring-fenced for state pension and contributory benefits, with surplus topping up general revenue. In practice the modern system has loosened the contribution-benefit link (the NHS is funded from general taxation despite NI's history), but the state pension entitlement still depends on qualifying years of contributions or credits, making NI the most consequential tax most workers face for long-term retirement planning.

How it works: rates and thresholds 2026/27

Employee Class 1 NI 2026/27:
  0%   Earnings up to GBP 12,570 (Primary Threshold, weekly GBP 242)
  8%   GBP 12,571 to GBP 50,270 (Upper Earnings Limit, weekly GBP 967)
  2%   Above GBP 50,270

Self-employed Class 4 NI 2026/27:
  0%   Profits up to GBP 12,570 (Lower Profits Limit)
  6%   GBP 12,571 to GBP 50,270
  2%   Above GBP 50,270

Employer Class 1 Secondary NI 2026/27:
  0%     Earnings up to GBP 5,000 (Secondary Threshold)
  15%    Above GBP 5,000 (raised from 13.8% in April 2025)
  Employment Allowance: up to GBP 10,500 off the bill for small employers

Voluntary contributions:
  Class 3 GBP 17.75/week
  Class 2 (voluntary) GBP 3.65/week (self-employed only)

State pension:
  Full new state pension 2026/27 = GBP 230.25/week (GBP 11,973/year)
  Need 35 qualifying years for full; 10 for any
  Each year adds 1/35th of the full amount

Worked example

Tom earns GBP 60,000 as an employee in 2026/27 with no benefits in kind. Here is his annual NI calculation:

  1. Earnings between GBP 12,570 and GBP 50,270 (the 8 percent band): GBP 50,270 - GBP 12,570 = GBP 37,700. NI at 8 percent = GBP 3,016.
  2. Earnings above GBP 50,270 (the 2 percent band): GBP 60,000 - GBP 50,270 = GBP 9,730. NI at 2 percent = GBP 194.60.
  3. Total employee NI: GBP 3,210.60.
  4. Income tax on Tom's GBP 60,000 (rUK, code 1257L): 20 percent on GBP 37,700 plus 40 percent on GBP 9,730 = GBP 7,540 + GBP 3,892 = GBP 11,432.
  5. Total tax and NI: GBP 14,642.60 (24.4 percent effective rate).
  6. Net take-home: GBP 45,357.40 per year, around GBP 3,780 per month.
Employer also pays: NI at 15 percent on (GBP 60,000 - GBP 5,000) = GBP 8,250. The "true cost" to Tom's employer is GBP 68,250 to deliver him GBP 45,357 in cash, a 33.6 percent total deduction wedge between gross employment cost and net pay.

Building your state pension

Every tax year in which you earn above the Lower Earnings Limit (GBP 6,396 for 2026/27, paid or credited) adds one qualifying year to your NI record. After 35 qualifying years you receive the full new state pension; partial records produce proportionate amounts. Common gap-fillers include voluntary Class 3 contributions and NI credits for child benefit, carer's allowance, and jobseeker's allowance.

Qualifying years2026/27 weekly amount2026/27 annual amount
10 (minimum)GBP 65.79GBP 3,421
20GBP 131.57GBP 6,842
30GBP 197.36GBP 10,263
35 (full)GBP 230.25GBP 11,973

A voluntary Class 3 contribution costs GBP 923 (GBP 17.75 x 52) and adds 1/35th of the full pension, currently GBP 342 per year. The contribution pays itself back in 2.7 years of retirement and continues paying out for life, the highest-return income product available to most UK retirees.

Related terms

PAYEPersonal AllowanceSIPPISADividend AllowanceCapital Gains Allowance

Related calculators on 3Tej

Calculate your NI deductions, take-home pay, and state pension forecast with these free UK tools:

UK Salary CalculatorUK Take-Home PayUK ISA CalculatorUK SIPP CalculatorUK Mortgage Calculator

Frequently asked questions

What are the 2026/27 National Insurance rates for employees?

Employees pay Class 1 NI at 8 percent on earnings between GBP 12,570 (the Primary Threshold) and GBP 50,270 (the Upper Earnings Limit), and 2 percent on earnings above GBP 50,270. There is no employee NI on earnings up to GBP 12,570. The 8 percent main rate was cut from 10 percent in April 2024 and from 12 percent in January 2024, but has been held at 8 percent for 2025/26 and 2026/27.

How many qualifying years do I need for a full UK state pension?

The new state pension (for those reaching State Pension Age after 6 April 2016) requires 35 qualifying years of NI contributions or credits for the full GBP 230.25 per week (GBP 11,973 per year) headline rate in 2026/27. You need at least 10 qualifying years to receive any new state pension. You can check your record and forecast at gov.uk and fill gaps with voluntary Class 3 contributions, currently GBP 17.75 per week.

What is the difference between Class 1, 2, 3, and 4 NI?

Class 1 is paid by employees (8 percent and 2 percent) and employers (13.8 percent above the Secondary Threshold of GBP 5,000 in 2026/27). Class 2 is the flat self-employed contribution (abolished as a mandatory tax from April 2024 but still available voluntarily to fill state pension gaps for the self-employed). Class 3 is voluntary, paid by anyone wanting to top up their record (GBP 17.75 per week in 2026/27). Class 4 is paid by the self-employed on profits, 6 percent between GBP 12,570 and GBP 50,270 and 2 percent above.

Do I pay National Insurance after State Pension Age?

No. You stop paying employee Class 1 and self-employed Class 4 NI from the State Pension Age (66 for those reaching it in 2026/27, rising to 67 from 2028). You should give your employer a letter or certificate from HMRC confirming your age so they stop deducting NI. Income tax still applies normally above your Personal Allowance, but NI does not. Employer NI continues to be paid by the employer.

Why does my National Insurance number matter?

Your National Insurance number is your unique reference linking you to your NI contribution record, your state pension forecast, your tax records (PAYE and Self Assessment), benefits, and student loan account. Without one you cannot legally work in the UK or claim most benefits. You typically receive an NI number just before you turn 16; adults who need one (immigrants, those who never received one) apply at gov.uk.

Should I make voluntary NI contributions to fill gaps?

Often yes. Voluntary Class 3 contributions cost GBP 17.75 per week (GBP 923 per year) in 2026/27 and each year added increases your weekly state pension by 1/35th of the full amount, currently GBP 6.58 per week (GBP 342 per year). That payback period is under 3 years if you live to draw state pension. Special transitional rules allow filling gaps as far back as April 2006 until 5 April 2027; check your NI record at gov.uk before paying anything.

Sources and further reading

Last updated 2026-05-28.