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Class 4 NI ยท Self-Employed UK 2025/26

Class 4 National Insurance

๐Ÿ“… Last updated: June 2026 ยท FreelanceRateCalculator.com ยท For guidance only โ€” always verify with HMRC or a qualified accountant.

Class 4 National Insurance is the main NI charge for self-employed people in the UK. Here are the current rates, thresholds and how it combines with income tax.

What Is Class 4 NI?

Class 4 National Insurance is a percentage-based NI charge paid by self-employed people on their annual profits. It is calculated as part of your Self Assessment return and paid alongside income tax. Unlike Class 2 (a flat weekly rate), Class 4 scales with your earnings โ€” the more profit you make, the more Class 4 NI you owe.

Class 4 does not count towards State Pension entitlement โ€” that comes from Class 2 contributions. Class 4 contributes to general government revenue.

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Class 4 NI Rates and Thresholds 2025/26

Profit BandClass 4 Rate
Up to ยฃ12,570 (Lower Profits Limit)0%
ยฃ12,571 โ€“ ยฃ50,270 (Upper Profits Limit)9%
Above ยฃ50,2702%

Source: HMRC / gov.uk ยท Rates correct for 2025/26 tax year.

At a profit of ยฃ40,000, your Class 4 NI is 9% ร— (ยฃ40,000 โˆ’ ยฃ12,570) = ยฃ2,468.70. At ยฃ60,000 it is 9% ร— (ยฃ50,270 โˆ’ ยฃ12,570) + 2% ร— (ยฃ60,000 โˆ’ ยฃ50,270) = ยฃ3,387.60. Class 2 NI (ยฃ179.40/year) is added on top.

Class 2 vs Class 4 NI

Self-employed workers pay both Class 2 and Class 4 NI. Class 2 is a flat rate (ยฃ3.45/week, ยฃ179.40/year) and protects State Pension entitlement. Class 4 is the main charge โ€” a percentage of profits. Both are collected through Self Assessment. For most freelancers, Class 4 is by far the larger amount.

Previously collected separately, Class 2 NI is now included in the Self Assessment calculation and paid at the same time as Class 4 and income tax on 31 January.

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Frequently Asked Questions

FAQ
What is the Class 4 NI threshold?+
Class 4 NI begins when profits exceed the Lower Profits Limit, which is ยฃ12,570 for 2025/26 โ€” aligned with the personal allowance. Below this, no Class 4 NI is owed.
When do I pay Class 4 NI?+
Class 4 NI is calculated as part of your Self Assessment tax return and paid by 31 January following the end of the tax year. It is not deducted automatically โ€” you calculate it via Self Assessment or using tax software.
Does Class 4 NI affect pension entitlement?+
No. Class 4 NI does not count towards State Pension qualifying years. Only Class 2 NI (and Class 1 from employment) builds pension entitlement. Class 4 is purely a revenue contribution.