National Insurance Increase Calculator UK

What Is National Insurance?

National Insurance (NI) is the UK's second big deduction from pay, sitting alongside Income Tax on your payslip. While Income Tax funds general government spending, NI is notionally linked to your entitlement to the State Pension and certain benefits — your NI record determines whether you qualify for the full new State Pension and benefits like contribution-based Jobseeker's Allowance. In practice, both come out of the same pay packet, which is why people often ask about them together — but they're calculated under completely separate rules, with their own rates and thresholds.

There are several "classes" of NI. If you're employed, you pay Class 1 (and your employer pays Class 1 too, at a different rate). If you're self-employed, you pay Class 2 (a flat weekly amount) and Class 4 (a percentage of your profits). The rates and thresholds below are for the 2026/27 tax year (6 April 2026 to 5 April 2027), taken from GOV.UK's National Insurance rates pages.

One thing that surprises people: unlike Income Tax, NI has no equivalent of the £12,570 tax-free Personal Allowance working quite the same way — instead it has its own set of thresholds (the Primary Threshold, Upper Earnings Limit and others), and the rates change depending on which band your earnings fall into. The calculator above handles all of this; the sections below explain what's going on.

Why Your National Insurance Changes Between Tax Years

NI isn't frozen in stone — the government reviews rates, thresholds and allowances ahead of each tax year, usually announced in the Autumn Budget. That's why a "national insurance increase calculator" exists at all: the number on your payslip this year may not match last year's, even if your salary hasn't moved.

The change people feel most in 2026/27 is on the employer side: employers now pay 15% on earnings above the Secondary Threshold, with the Employment Allowance raised to £10,500 to cushion smaller employers. For employees, the headline rates are 8% on the main band of earnings and 2% above it — the structure is the same as recent years, but the thresholds that define those bands are what move. Even a threshold frozen while wages rise means more of your pay gets pulled into NI — the classic "fiscal drag" — so checking the current-year figures matters even when the percentages look unchanged.

This page compares the 2026/27 position against 2025/26 so you can see exactly what changed for your pay packet — and your business costs, if you're an employer.

A quick note on "fiscal drag", because it's the quiet driver of most year-on-year increases: when thresholds stay frozen but wages rise with inflation, a bigger slice of your pay creeps into the 8% band. Someone whose salary rose from £33,000 to £35,000 might assume their NI rose proportionally — but because the £242/week starting line didn't move, slightly more than the £2,000 rise attracted 8%. The calculator's comparison view shows this effect in pounds, which is the only number that actually matters to your budget.

What to Look for in the Year-on-Year Comparison

The calculator's comparison view shows your NI bill for 2025/26 next to 2026/27. Here's how to read it:

• The annual difference in pounds — this is the headline. A £40 rise on a £35,000 salary is threshold creep, not a rate change; a jump of hundreds suggests a rate or band change hit your pay level.
• Where the change came from — check whether the extra pounds sit in the 8% band (threshold movement) or appeared above £967/week (a change affecting higher earners). The two have very different implications for next year's negotiations.
• Employer-side changes — if you run payroll, compare the employer column separately. The 15% rate and £10,500 Employment Allowance dominate this view; a business whose allowance covers the whole bill will show £0 payable even as gross employer NI rises.
• Monthly, not just annual — divide the annual difference by 12 before deciding whether it matters. £120 a year is £10 a month: real money, but not a reason to replan your finances.

National Insurance Rates and Thresholds 2026/27

Here are the verified 2026/27 figures, all from GOV.UK. Employee Class 1 is what most readers are here for; the self-employed and employer figures follow.

Employees (Class 1)

Source: GOV.UK — National Insurance: how much you pay.

Self-employed (Class 2 and Class 4)

• Class 4: 6% on profits between £12,570 and £50,270; 2% on profits above £50,270.
• Class 2: £3.65 per week (flat rate).

Source: GOV.UK — National Insurance: how much you pay.

Employers (on employee earnings)

• Rate: 15% on earnings above the Secondary Threshold, for the year 6 April 2026 to 5 April 2027.
• Secondary Threshold (ST): £5,000 a year.
• Employment Allowance: £10,500 a year — eligible employers can offset this against their NI bill.

Source: GOV.UK — National Insurance rates and category letters.

Key thresholds at a glance (2026/27)

How to Use the National Insurance Calculator

The calculator compares what you (or your employees) pay in NI between tax years. To get an accurate result:

• Employment status: choose employed or self-employed — the classes, rates and thresholds are completely different.
• Annual salary or profits: enter gross annual pay (before tax and NI) or, if self-employed, your annual taxable profits.
• Pay frequency: the calculator converts to weekly/monthly internally because the 8% band is defined weekly (£242–£967). Entering the wrong frequency is the most common input error.
• Tax years to compare: select 2025/26 vs 2026/27 (or a single year) to see the increase — or decrease — in pounds per year and per month.

Employers: there's a separate section for employer-side costs using the 15% rate, the £5,000 Secondary Threshold and the £10,500 Employment Allowance.

How Employee National Insurance Is Calculated

Employee NI is charged in slices, a bit like Income Tax bands. You pay nothing on earnings up to the Primary Threshold (£12,570 a year), 8% on the slice between £242 and £967 a week, and 2% on anything above £967 a week. Two worked examples make this concrete.

Example 1 — £35,000 salary

• Weekly pay: £35,000 ÷ 52 = £673.08
• 8% band: £673.08 − £242 = £431.08 → 8% × £431.08 = £34.49/week
• 2% band: £673.08 is below £967, so £0
• Annual employee NI: £34.49 × 52 = £1,793.35/year

Example 2 — £60,000 salary

• Weekly pay: £60,000 ÷ 52 = £1,153.85
• 8% band: £967 − £242 = £725 → 8% × £725 = £58.00/week
• 2% band: £1,153.85 − £967 = £186.85 → 2% × £186.85 = £3.74/week
• Total: £61.74/week × 52 = £3,210.35/year

Example 3 — £20,000 part-time salary

• Weekly pay: £20,000 ÷ 52 = £384.62
• 8% band: £384.62 − £242 = £142.62 → 8% × £142.62 = £11.41/week
• 2% band: below £967, so £0
• Annual employee NI: £11.41 × 52 = £593.32/year
• Note: at £20,000 you're comfortably above the £12,570 Primary Threshold, so NI applies — but the bill is modest because only the slice above £242/week is charged

Notice how the 2% rate keeps the bill surprisingly modest even at £60,000 — NI is much less progressive than Income Tax, which is exactly why the two deductions feel so different on a payslip.

Employee vs Self-Employed National Insurance

Self-employed NI works differently: instead of weekly bands, Class 4 applies to annual profits with the same £12,570–£50,270 band structure as the employee 8% band, and Class 2 is a simple flat weekly charge that buys your NI record.

Example — £40,000 self-employed profits

• Class 4: 6% × (£40,000 − £12,570) = 6% × £27,430 = £1,645.80
• Class 2: £3.65 × 52 = £189.80
• Total NI: £1,835.60/year

Compare that with an employee on £40,000: weekly £769.23 → 8% × (£769.23 − £242) = £42.18/week → £2,193.35/year. The self-employed total is lower, but remember the employee's employer is also paying 15% on top — the overall NI cost of employment is much higher than the employee's payslip suggests.

Employer National Insurance: The "Increase" Explained

This is where the "increase" in this calculator's name bites. Employers pay 15% on each employee's earnings above the £5,000 Secondary Threshold — and unlike employee NI, there's no upper limit and no 2% band. It applies to the full slice above £5,000.

Example — one employee on £30,000

• Earnings above the Secondary Threshold: £30,000 − £5,000 = £25,000
• Employer NI: 15% × £25,000 = £3,750/year
• Employment Allowance: eligible employers can deduct £10,500 from their total NI bill — which wipes out this £3,750 entirely, with £6,750 of allowance left for other staff

For a small business with a handful of staff on modest salaries, the £10,500 Employment Allowance often covers the whole employer NI bill — which is precisely why the allowance was raised. Larger employers, or those with highly-paid staff, feel the 15% rate directly. If you're budgeting payroll for 2026/27, run every salary through the calculator's employer section: the difference between the old and new cost is the number your cashflow plan needs.

National Insurance vs Income Tax

The two deductions are often confused because they leave your pay together, but they differ in almost every way that matters:

• Different thresholds: Income Tax starts at the £12,570 Personal Allowance; employee NI starts at the £12,570 Primary Threshold — the same number in 2026/27, but they move independently and have different histories.
• Different rate structures: Income Tax is 20%/40%/45%; employee NI is 8% then just 2% — far less progressive.
• Different upper limits: Income Tax keeps climbing; NI's main rate stops at £50,270 (the Upper Earnings Limit) and drops to 2%.
• Different purposes: NI builds your contribution record for the State Pension and certain benefits; Income Tax doesn't.
• Employer NI has no Income Tax equivalent: the 15% employer charge is a pure payroll cost with no parallel in the Income Tax system.

A practical consequence: when you get a pay rise, the two deductions take different bites. A £2,000 rise for a basic-rate taxpayer costs about £400 in Income Tax (20%) but only £160 in employee NI (8%) — because NI's main rate is less than half the basic Income Tax rate. That's why "take-home" calculators always show both lines separately: lumping them together hides where your money actually goes.

For the Income Tax side of your pay, see our Taxable Income Calculator and the 2026/27 UK tax brackets guide.

Common Mistakes When Comparing NI Between Tax Years

• Comparing percentages instead of pounds. An unchanged 8% rate can still cost you more if the thresholds moved — always compare the annual £ figure.
• Forgetting employer NI in salary negotiations. A £5,000 pay rise costs your employer £5,750 in NI terms (15% on top). Knowing this strengthens your hand — and your employer's budgeting.
• Mixing up weekly and monthly thresholds. The 8% band is £242–£967 weekly (£1,048–£4,189 monthly). Using monthly pay against weekly thresholds (or vice versa) doubles or halves your answer.
• Ignoring Class 2. Self-employed people sometimes calculate Class 4 and forget the £3.65/week Class 2 — it's only £189.80 a year, but it's what keeps your NI record (and State Pension) intact.
• Assuming the Employment Allowance is automatic. Eligible employers must claim it — it isn't applied by default. If you run payroll and haven't claimed, you're overpaying.
• Using last year's thresholds. Thresholds are the part that moves most often. Bookmark the GOV.UK rates page and check each April.

Frequently Asked Questions

What are the National Insurance rates for 2026/27?

Employees pay 8% on earnings between £242 and £967 a week (£1,048–£4,189 a month) and 2% above that. Self-employed workers pay Class 4 at 6% on profits between £12,570 and £50,270 (2% above) plus Class 2 at £3.65 a week. Employers pay 15% on earnings above the £5,000 Secondary Threshold, with a £10,500 Employment Allowance for eligible businesses. All figures from GOV.UK.

Why is it called a National Insurance "increase"?

Because the calculator's headline job is comparing tax years — and the employer rate increase to 15% (alongside the Employment Allowance rise to £10,500) is the change with the biggest cash impact in 2026/27. For employees, the rates themselves are stable, but threshold movements still change the pounds you pay, which is why the year-on-year comparison matters.

At what salary do I start paying National Insurance?

Employees start paying Class 1 NI when earnings pass the Primary Threshold of £12,570 a year (£242 a week) in 2026/27. Below that you pay 0% — though earnings above the £6,708 Lower Earnings Limit still count toward your NI record via credits, protecting your State Pension even when you're not paying.

Do I pay National Insurance on all my income?

No — and this is the key difference from a flat tax. You pay 0% below £12,570, 8% on the £12,570–£50,270 band (measured weekly as £242–£967), and only 2% above £50,270. Someone on £100,000 pays the 8% rate on less than half their salary; the rest attracts just 2%.

I'm self-employed — do I still pay Class 2?

Yes, Class 2 (£3.65/week in 2026/27) is the flat-rate contribution that maintains your NI record and State Pension entitlement, paid alongside the profit-based Class 4. On £40,000 of profits that's £189.80 for the year — small, but don't skip it in your calculations.

Can my employer pass their 15% NI cost on to me?

Not directly — employer NI is legally the employer's liability and can't be deducted from your wages. Indirectly, though, it's part of the total cost of employing you, which is why it features in pay negotiations and why some employers discuss "total cost to company" figures. Understanding the £3,750-on-£30,000 maths above helps you read those conversations accurately.

The Bottom Line

For 2026/27, the numbers to remember are 8% and 2% (employee), 6% and 2% plus £3.65/week (self-employed), and 15% (employer) — with thresholds at £12,570, £50,270, £6,708 and £5,000 doing the quiet work of deciding how much of your pay each rate touches. Run your salary through the calculator above, compare the years, and you'll know exactly where the increase lands. And if you're an employer, don't forget the £10,500 Employment Allowance: for many small businesses it's the difference between a painful bill and no bill at all.

Official Sources (GOV.UK, 2026/27)

• National Insurance — how much you pay (GOV.UK) — employee 8%/2% bands, Class 4 6%/2%, Class 2 £3.65/week
• National Insurance rates and category letters (GOV.UK) — employer 15%, thresholds, Employment Allowance
• Income Tax rates and Personal Allowances (GOV.UK) — for the Income Tax side of your payslip

Explore More UK Salary Calculators

Complete the picture with our Taxable Income Calculator, the Annual Salary Calculator UK for take-home pay, and the 2026/27 UK tax brackets guide.