National Insurance for the Self-Employed

As a self-employed person in the UK, you pay two classes of National Insurance (NI) — Class 2 and Class 4. These are separate from the Class 1 NI that employees pay through PAYE, and they work differently.

Class 2 National Insurance is a flat-rate weekly contribution. For the 2025/26 tax year, the rate is £3.45 per week (£179.40 per year). You pay Class 2 if your profits are at or above the Small Profits Threshold of £6,725. If your profits are below this threshold, you do not have to pay, but you can choose to make voluntary contributions.

Class 4 National Insurance is calculated as a percentage of your annual profits. For 2025/26:

• 9% on profits between £12,570 and £50,270
• 2% on profits above £50,270

Both classes are calculated and paid through your Self Assessment tax return. Unlike employees who pay NI monthly through their payslips, self-employed NI is paid alongside your income tax — either as a lump sum on 31 January or through payments on account.

It is important to understand that NI is separate from Income Tax. Even if you earn below the personal allowance (£12,570) and owe no Income Tax, you may still owe Class 2 NI if your profits exceed £6,725.

Let us walk through a practical example. Say your self-employed profit for 2025/26 is £35,000:

Class 2 NI:

Your profits are above the Small Profits Threshold (£6,725), so you pay the flat rate: 52 weeks x £3.45 = £179.40

Class 4 NI:

• No NI on the first £12,570 (the Lower Profits Limit)
• 9% on the amount between £12,570 and £35,000 = 9% x £22,430 = £2,018.70

Total NI for the year: £2,198.10

Now let us look at someone earning £60,000:

• Class 2: £179.40
• Class 4 at 9% on £12,570-£50,270 = 9% x £37,700 = £3,393.00
• Class 4 at 2% on £50,270-£60,000 = 2% x £9,730 = £194.60

Total NI: £3,767.00

These figures are calculated automatically when you file your Self Assessment return. HMRC's online system works them out based on the profit figure you report. The amounts are included in your overall tax bill alongside your Income Tax liability.

National Insurance is not just a tax — it is also what builds your entitlement to the State Pension and certain other benefits. This is why it matters beyond the immediate cost.

To qualify for the full new State Pension, you need 35 qualifying years of National Insurance contributions. You need at least 10 qualifying years to get anything at all. The full new State Pension for 2025/26 is £221.20 per week (approximately £11,500 per year).

What counts as a qualifying year?

• Paying Class 2 NI contributions as a self-employed person (this is the main one for freelancers)
• Paying Class 1 NI as an employee
• Receiving National Insurance credits (e.g., while claiming certain benefits, caring for a child under 12, or being registered as unemployed)

Class 4 NI does not count towards your State Pension — it is purely a tax on profits. Only Class 2 builds your pension entitlement. This is why Class 2, despite being a small amount (£179.40/year), is very valuable. You are essentially buying a year's worth of State Pension entitlement for under £180.

If your profits are below the Small Profits Threshold (£6,725), you are not required to pay Class 2, but you can opt to pay it voluntarily. Given that a full qualifying year costs just £179.40 but adds approximately £329 per year to your eventual State Pension (£11,500 divided by 35 years), voluntary Class 2 contributions offer an exceptional return on investment.

There are situations where you might want to make voluntary National Insurance contributions to fill gaps in your record:

When you might have gaps:

• Years when you earned below the Small Profits Threshold and did not pay Class 2
• Years spent living or working abroad
• Years when you were not working and not claiming benefits
• Career breaks for travel, education, or personal reasons

Class 2 voluntary contributions are available to self-employed people earning below £6,725. At £3.45 per week, they are the cheapest way to build qualifying years.

Class 3 voluntary contributions are available to everyone and cost £17.45 per week (£907.40 per year) for 2025/26. These are significantly more expensive than Class 2 but serve the same purpose of adding qualifying years to your record.

How to check your record: Log in to your Personal Tax Account on gov.uk and select "Check your National Insurance record." This shows your contribution history year by year, highlights any gaps, and tells you how many qualifying years you have. It also shows your State Pension forecast based on your current record.

You can usually fill gaps going back six years. For example, in the 2025/26 tax year, you can pay voluntary contributions for years back to 2019/20. There is currently an extended deadline allowing contributions back to 2006, but this window may close — check gov.uk for the latest position.

Many people run a freelance business alongside a PAYE job. If this applies to you, you may be paying NI through both routes, and there are special rules to prevent overpayment.

How it works:

• Your employer deducts Class 1 NI from your salary through PAYE as normal
• You also pay Class 2 and Class 4 NI on your self-employed profits through Self Assessment
• If your combined NI contributions exceed the annual maximum, you can apply for a refund or deferment

The annual maximum: There is a cap on the total Class 1, Class 2, and Class 4 NI you pay in a single year. This is calculated by HMRC and is roughly equivalent to paying the main rate (8% for employees, 9% for self-employed) on income up to the Upper Earnings Limit (£50,270), plus 2% on everything above that.

Deferment: If you know in advance that your combined employment and self-employment income will put you over the maximum, you can apply to defer your Class 4 NI payments. This prevents you from overpaying and then having to claim a refund. Apply using form CA72A before the start of the tax year.

In practice, HMRC's Self Assessment system usually handles this correctly. But if you have high earnings from both sources, it is worth checking the calculation on your tax return. If you overpay, HMRC should issue a refund automatically, but it can take time.

One important note: even if you defer Class 4, always pay your Class 2 contributions. They are only £3.45 per week and they build your State Pension record.

Unlike Income Tax, there are fewer ways to reduce your National Insurance bill. NI does not benefit from many of the reliefs and allowances that reduce Income Tax. However, there are some strategies:

Claim all allowable expenses. Since NI is calculated on your profit (income minus expenses), every legitimate business expense you claim reduces both your Income Tax and your Class 4 NI. A £1,000 expense saves you £90 in Class 4 NI (at the 9% rate) on top of the Income Tax saving.

Consider incorporation. If you are a sole trader vs limited company, the NI treatment is very different. Company directors who pay themselves primarily through dividends avoid Class 4 NI entirely — dividends are not subject to National Insurance. This is one of the main tax advantages of operating through a limited company once your profits are high enough. However, you would still pay Class 1 NI on any salary you take from the company.

Timing of income and expenses. If you are close to the Upper Profits Limit (£50,270), bringing forward expenses or deferring income to keep profits below that threshold means you pay 9% rather than having some profit taxed at the 2% rate above it. However, this is a marginal saving and rarely worth distorting your business operations for.

What you cannot do: Unlike pension contributions which reduce Income Tax, NI has no equivalent relief. You cannot reduce your NI bill by making pension contributions — NI is calculated before pension relief. This surprises many self-employed people, so factor it into your tax planning.