Most people know National Insurance comes out of their payslip alongside Income Tax, but far fewer know what it actually buys them, or why it exists as a separate deduction at all rather than just being folded into tax. The honest answer is a bit more interesting than "it's just another tax," and understanding it properly can genuinely change decisions, like whether it's worth paying voluntary contributions to fill a gap in your record.
This guide covers what National Insurance funds, how the rates work for 2026/27, and what you're actually entitled to because of it. For how NI affects your specific take-home pay, use our take-home pay calculator, which factors it in automatically.
What National Insurance Actually Pays For
National Insurance isn't paid into the same pot as Income Tax. A portion of what you and your employer contribute goes directly to the NHS, based on a fixed formula set out in law, and the rest goes into something called the National Insurance Fund.
The National Insurance Fund is legally separate from general government spending, and it exists specifically to pay for contributory benefits, things you're entitled to because you've paid in, not just because you're a UK resident. The main one, by a wide margin, is the State Pension. The Fund also pays for contribution-based Jobseeker's Allowance, contribution-based Employment and Support Allowance, and bereavement benefits.
It works on a pay-as-you-go basis rather than as a personal savings pot. Contributions collected this year pay for pensions and benefits being claimed this year, not for your own pension decades from now. There's no individual account with your name on it building up a balance, which is a common misconception. What you do build up is entitlement, a record of qualifying years that determines how much State Pension you'll receive.
Why Is National Insurance Separate From Income Tax?
The answer is partly historical, partly practical, and the two have drifted apart over time.
National Insurance was introduced in 1911 as a contributory insurance scheme, the idea being that paying in gave you personal entitlement to specific benefits if you fell ill, lost your job, or reached retirement. It was expanded significantly in 1948 alongside the creation of the NHS and the modern welfare state. Income Tax, by contrast, has never worked this way. It funds general government spending, with no direct link between what you pay and what you personally get back.
In practice, that distinction has blurred. The Institute for Fiscal Studies has pointed out there's no real sense in which raising more or less National Insurance in a given year changes how much gets spent on healthcare or benefits, and successive governments have used NI thresholds and rates as a general tax lever, not just a contribution mechanism. So while the historical logic explains why the two are calculated separately, National Insurance today functions much closer to a second income tax than its original design intended, just one that also builds entitlement to the State Pension.
For more on how PAYE actually collects Income Tax, what it pays for, and how the two systems compare in practice, see our PAYE and Income Tax explained guide.
National Insurance Rates for 2026/27
Employees
| Band | Earnings | Rate |
|---|---|---|
| Below Primary Threshold | Up to £12,570/year | 0% |
| Main rate | £12,571 – £50,270/year | 8% |
| Above Upper Earnings Limit | Over £50,270/year | 2% |
So someone earning £35,000 pays 8% on everything between £12,570 and £35,000, which works out at £1,794 a year. Someone earning £70,000 pays 8% up to £50,270, then 2% on the remaining £19,730, working out at £3,014 plus £395, or £3,409 total.
Here's how annual employee National Insurance looks across a range of salaries:
| Gross salary | Annual National Insurance |
|---|---|
| £25,000 | £994 |
| £35,000 | £1,794 |
| £45,000 | £2,594 |
| £60,000 | £3,211 |
| £80,000 | £3,611 |
| £100,000 | £4,011 |
Notice how the increase slows sharply above £50,270. That's the 2% band taking over from the 8% band, so a much bigger salary only adds a small amount of extra NI once you're past the Upper Earnings Limit.
Employers
Employers pay National Insurance too, and at a considerably higher rate than employees, though this doesn't come out of your pay directly. It's a cost on top of your salary that your employer bears separately.
| Band | Earnings | Rate |
|---|---|---|
| Below Secondary Threshold | Up to £5,000/year per employee | 0% |
| Above Secondary Threshold | Over £5,000/year | 15% |
There's no upper limit on employer contributions, unlike the employee side, which drops to 2% above £50,270. Eligible small employers can claim Employment Allowance, currently up to £10,500, which offsets some or all of this cost. It's not something you'll see on your payslip, but it's worth understanding, because it's a genuine part of the cost of employing someone, and it's occasionally cited by employers explaining why total headcount costs are higher than gross salaries alone suggest.
Self-Employed
If you're self-employed, you pay Class 4 National Insurance on your profits rather than Class 1.
| Band | Profits | Rate |
|---|---|---|
| Below threshold | Up to £12,570/year | 0% |
| Main rate | £12,571 – £50,270/year | 6% |
| Above threshold | Over £50,270/year | 2% |
Class 2 contributions, a separate flat weekly charge that used to apply to the self-employed, were abolished in April 2024. If your profits are above the Small Profits Threshold, currently £7,105, you're now treated as having paid Class 2 for the purposes of building State Pension entitlement, without actually having to pay it. If your profits fall below that threshold, you can still choose to pay voluntary Class 2 contributions to keep your entitlement intact.
What You Actually Get From Paying National Insurance
The State Pension is the big one, and it works on a system of qualifying years rather than a running total of how much you've paid in. This is separate from any workplace or private pension you might also have, covered in full in our workplace pensions explained guide.
You need 35 qualifying years on your National Insurance record to get the full new State Pension, which is £241.30 a week for 2026/27, working out at roughly £12,548 a year. You need a minimum of 10 qualifying years to get anything at all. Between 10 and 35 years, your pension is calculated proportionally, so 20 qualifying years gets you roughly 20/35ths of the full amount. Once you've reached 35 years, extra years don't add anything further, beyond a specific edge case involving pre-2016 pension entitlements that most people won't encounter.
A qualifying year is a tax year in which you've earned above the Lower Earnings Limit, currently £6,708 a year, or received National Insurance credits. This is where a genuinely useful, widely-missed detail sits: the Lower Earnings Limit is meaningfully below the Primary Threshold of £12,570 where you actually start paying NI. If you earn somewhere between those two figures, you're treated as having paid National Insurance for that year, and it counts as a full qualifying year, even though nothing is actually deducted from your pay. Plenty of part-time workers and people on lower salaries build up full qualifying years without ever seeing an NI deduction on their payslip.
Credits work the same way for people who aren't earning at all in a given year. If you claim Child Benefit for a child under 12, you get NI credits automatically, even if you've taken time out of work entirely. The same applies if you're claiming Carer's Allowance, Jobseeker's Allowance, or Employment and Support Allowance. This matters a lot for anyone taking extended parental leave or time out to care for a family member, since it protects your State Pension record without you needing to do anything beyond claiming the benefit you're already entitled to.
Worth checking: You can see your own National Insurance record and State Pension forecast for free on GOV.UK using a Government Gateway login. It shows exactly how many qualifying years you have and flags any gaps, which is worth doing well before retirement age rather than discovering a shortfall too late to fix easily.
Filling Gaps With Voluntary Contributions
If you've got gaps in your record, whether from time abroad, a career break, or years of low earnings, you can usually fill them by paying voluntary Class 3 contributions, currently £18.40 a week for 2026/27. You can generally go back up to six tax years.
Whether it's worth doing comes down to straightforward maths. A full year of voluntary contributions costs roughly £956.80 as a lump sum, and buying it typically adds about £358 a year to your State Pension for the rest of your life. If you live more than about three years past State Pension age, which the vast majority of people do, you've recouped the cost and everything after that is pure upside. It's one of the better-value financial decisions available to most people, but it's specific to your own record, so checking your actual forecast before paying anything is essential rather than optional.
Common Misunderstandings
A lot of people assume National Insurance is simply "another income tax" with no real difference beyond the name. There's some truth in that day-to-day, but the entitlement link to the State Pension is real, and it's the reason gaps in your NI record can matter more than most people realise until they check their pension forecast and find a shortfall.
It's also easy to assume that paying more National Insurance over the years means a bigger pension. It doesn't, past 35 qualifying years the amount is capped, and extra years add nothing further under the new State Pension rules.