National Insurance: Class 4 main rate (self-employed)

The main Class 4 rate on self-employed profits between the lower and upper profits limits.

Corroborated Act of Parliament Great Britain in force since 2024-04-06

Checked against its sources: statute verified 2026-09-21·guidance verified 2026-09-21

Scope: s.15(3ZA) states that the main Class 4 percentage is subject to alteration under s.143 of the Social Security Administration Act 1992, so a Treasury order can change it without amending this text. The rate fell from 9% to 6% across 2024 by amendments to this provision.

Current sources

Source A · LegislationSocial Security Contributions and Benefits Act 1992, c. 4 s. 15(3ZA)(a) ("the main Class 4 percentage is 6%")

retrieved 2026-07-29

Source B · Official guidancehttps://www.gov.uk/self-employed-national-insurance-rates (Class 4 rates for 2026 to 2027)

retrieved 2026-07-29

History

Value	From	To	Status	Sources
6%	2024-04-06	—	Corroborated	Legislation: Social Security Contributions and Benefits Act 1992, c. 4 s. 15(3ZA)(a) ("the main Class 4 percentage is 6%") retrieved 2026-07-29 Official guidance: https://www.gov.uk/self-employed-national-insurance-rates (Class 4 rates for 2026 to 2027) retrieved 2026-07-29

Receipt

Everything above is reproducible and independently checkable — no trust in this site required (how verification works).

Figure ID: employment.ni.class4.main_rate
Name in the API: Class 4 National Insurance: main rate
Record fields (source type · unit · jurisdiction · status): act·percent·GB·corroborated
Record hash (canonical JSON, SHA-256): sha256:ed6ee0dea41216cec24d30bc35d7860dcf7fbdfb527f2608bf132157851b5f8a
Source snapshots (SHA-256): Legislation: sha256:70bfaaf5415fca7984030bcdfe31c32b6f6ef14664f6ae511128e84c2ea44536; Official guidance: sha256:a1df49d039b43cc6cabc82ee24bc2d9779d910c3fd7a016999bc70db0550bd96
Listed in the signed manifest: release 3.0.0 manifest · record_hashes["employment.ni.class4.main_rate"]
Machine-readable record: /v1/figures/employment.ni.class4.main_rate · current only: /v1/figures/employment.ni.class4.main_rate/current

Compiler's notes

The checklist warned that this figure was drafted as the spelt form "9 per cent" and would need the percentage parser extending. The current text reads "6%", so the warning is spent: the digit form is what the Act now carries. WS6-ACT-CLASS-SWEEP.md records the probe. effective_from is read from the F-note on the archived section: "Figure in s. 15(3ZA)(a) substituted (6.4.2024) by National Insurance Contributions (Reduction in Rates) Act 2024 (c. 5), ss. 1(3)(a), 3(1)" — the amendment that made the main rate 6%.