National Insurance Explained (2026/27)

National Insurance (NI) is often lumped in with Income Tax on a payslip, but it's a genuinely separate system with its own rules, thresholds, and purpose — your NI contributions record directly determines your entitlement to the State Pension and certain other benefits. This guide covers how it actually works.

For the current rates in context with everything else, see the Personal Finance Wiki. To see your own numbers, use the UK Take-Home Pay Calculator.

Contents

  1. What NI actually pays for
  2. The different classes of NI
  3. Employee (Class 1) rates for 2026/27
  4. How it's different from Income Tax
  5. Qualifying years and gaps in your record
  6. Voluntary contributions
  7. FAQ

What NI actually pays for

Unlike Income Tax, which funds general government spending, National Insurance contributions are notionally ring-fenced to fund specific contributory benefits — most importantly:

In practice, NI receipts are pooled with general taxation to fund the NHS and other spending too — but your personal entitlement to the State Pension and related benefits is tracked separately, based on your NI record.

The different classes of NI

ClassWho pays itWhat for
Class 1Employees, deducted via payrollStandard employee NI
Class 1AEmployers, on benefits in kind (company cars, private healthcare, etc.)Employer-only charge
Class 2Previously self-employed with profits above a thresholdAbolished from April 2024 — see below
Class 3Anyone, voluntarilyFilling gaps in your NI record
Class 4Self-employed, on profitsSelf-employed equivalent of Class 1

Class 2 NI was abolished for most self-employed people from 6 April 2024 — those with profits above the Small Profits Threshold (£7,105 for 2026/27) now get a qualifying year automatically without paying Class 2, while those below it can still pay voluntarily (£3.65/week for 2026/27) to protect their record. See the Self-Employed vs Employed Tax Guide for the full picture.

Employee (Class 1) rates for 2026/27

ThresholdAnnualWeeklyRate
Below Primary ThresholdUp to £12,570Up to £2420%
Primary Threshold to Upper Earnings Limit£12,570 – £50,270£242 – £9678%
Above Upper Earnings LimitOver £50,270Over £9672%

Employers pay a separate charge (Class 1 secondary) on top — 15% above a £5,000/year secondary threshold — but this doesn't come out of your pay; it's an additional cost to your employer.

How it's different from Income Tax

Three key differences trip people up:

  1. NI is calculated per pay period, not cumulatively across the year. Income Tax uses a cumulative system that smooths out fluctuations (a quiet month makes up for a big bonus month). NI generally doesn't — each payslip is assessed independently against that period's threshold. A bonus paid in one month is charged NI at that period's marginal rate and this is not corrected later, unlike Income Tax. See the Bonus & Overtime Tax Guide for more on this.
  2. NI has no annual "top-up" reconciliation for most employees. If your income varies a lot month to month, you can end up paying more total NI over the year than someone with the same annual salary paid evenly — because each period's calculation stands on its own.
  3. NI stops once you reach State Pension age. Income Tax doesn't — you keep paying Income Tax on income (including a workplace pension or continued employment) for the rest of your life if it exceeds your Personal Allowance, but NI liability ends once you hit State Pension age, even if you keep working.

Qualifying years and gaps in your record

You need 35 qualifying years of NI contributions or credits for the full new State Pension, and a minimum of 10 years for any State Pension at all. A "qualifying year" is one where you either:

Gaps commonly occur during career breaks, time spent living or working abroad, or periods of low income. You can check your record and any gaps via your Personal Tax Account on gov.uk.

Voluntary contributions

If you have gaps, you can usually pay Class 3 voluntary contributions (£18.40/week for 2026/27) to fill them — often a strong value proposition, since a single qualifying year currently adds roughly £6.89/week (≈£358/year) to the new State Pension for life, meaning the cost is typically recovered within a few years of retirement. There are time limits on how far back you can pay for most people (usually 6 years), though transitional arrangements have periodically extended this — check current rules on gov.uk before assuming a historic gap can still be filled.

FAQ

Do I still pay National Insurance after State Pension age?

No — NI liability stops once you reach State Pension age, even if you continue working. Income Tax still applies as normal.

Why did my NI seem higher in the month I got a bonus?

Because NI is calculated per pay period rather than smoothed across the year like Income Tax, a bonus added to one month's pay is taxed at that period's marginal NI rate — and unlike Income Tax, this isn't corrected in later months.

What's the difference between NI and Income Tax?

Income Tax funds general government spending and is calculated cumulatively across the tax year. National Insurance funds specific contributory benefits (mainly the State Pension), is calculated per pay period, and stops at State Pension age.

How many qualifying years do I need for a full State Pension?

35 years for the full new State Pension, with a minimum of 10 years required for any State Pension entitlement at all.

Is it worth paying voluntary Class 3 contributions?

Often yes, if you have gaps that would otherwise reduce your State Pension — the cost is typically recovered within a few years of retirement, though it depends on your specific circumstances and how many years you already have.

More guides

This page is for general information only and does not constitute financial advice. Figures are correct for the 2026/27 tax year. For your specific NI record, check your Personal Tax Account on gov.uk.