Class 4 National Insurance for the Self-Employed 2026/27: Rates, Thresholds and How to Pay

What Is Class 4 National Insurance?

Class 4 National Insurance is the contribution paid by self-employed people in the UK on their trading profits. Unlike employees, who pay Class 1 NI through PAYE, sole traders and partners in a business pay Class 4 through their Self Assessment return.

For 2026/27, the rates are:

• 6% on profits between GBP 12,570 and GBP 50,270
• 2% on profits above GBP 50,270

Class 4 NI does not entitle you to any additional benefits directly. It is a general contribution to the National Insurance Fund. Your entitlement to the State Pension and other contributory benefits comes from your NI record, which is built separately.

How Class 4 Differs from Class 2

Before April 2024, self-employed people paid two types of NI: Class 2 (a flat weekly amount) and Class 4 (profit-based). Class 2 was abolished from the 2024/25 tax year onwards.

Under the current rules for 2026/27:

• If your profits exceed GBP 6,845 (the Small Profits Threshold), your NI record is credited automatically through Self Assessment. You do not pay any separate Class 2 charge.
• If your profits fall below GBP 6,845, you receive no automatic credit. You can make voluntary contributions at GBP 3.45 per week to maintain your State Pension record.

This is an important distinction. Low-income self-employed workers who were previously protected by Class 2 credits must now take deliberate action if their profits are minimal.

How to Pay Class 4 National Insurance

Class 4 NI is not a separate payment you arrange yourself. When you file your Self Assessment return for 2026/27 (deadline 31 January 2028 for online returns), HMRC calculates the amount owed based on your declared profits.

The payment timeline works as follows:

• 31 January 2027: First payment on account for 2026/27 (based on 50% of prior year liability)
• 31 July 2027: Second payment on account
• 31 January 2028: Balancing payment or refund once 2026/27 return is filed

If you are newly self-employed, you will not make payments on account in your first year. Your full liability is due on 31 January following the tax year end.

Worked Example: Class 4 NI for a Freelancer Earning GBP 45,000

Suppose your self-employed profits for 2026/27 are GBP 45,000 after expenses.

• Profits between GBP 12,570 and GBP 45,000: GBP 32,430 at 6% = GBP 1,945.80
• No profits above GBP 50,270 in this example

Total Class 4 NI liability: GBP 1,945.80

You would also owe Income Tax on the same profits (minus your Personal Allowance of GBP 12,570), so your combined Self Assessment bill would be considerably higher.

Tips to Manage Your Class 4 Bill

Claiming all legitimate business expenses before calculating profits is the most direct way to manage your Class 4 NI. Common deductions include professional subscriptions, equipment used for work, a proportion of home costs if you work from home, and business travel.

Making pension contributions to a registered personal pension scheme reduces your adjusted net income, which can push profits below a higher threshold and reduce both Income Tax and NI in certain scenarios.

Setting aside around 25-30% of your profits each month into a separate savings account is a widely recommended practice to ensure you are not caught short when your Self Assessment bill arrives.