{
  "meta": {
    "schema": "statbook-api/1",
    "release_version": "3.0.0",
    "compiled_at": "2026-09-21T00:00:00Z",
    "generated_at": "2026-09-28T09:07:46Z",
    "attribution": [
      "© Crown and database right. Derived from content available under the Open Government Licence v3.0 from legislation.gov.uk.",
      "Contains public sector information licensed under the Open Government Licence v3.0."
    ],
    "docs": "https://statbook.co.uk/docs/",
    "signing": {
      "scheme": "minisign",
      "public_key": "RWSPzbJEmAXVEvTqYZ8O9iHuOcOUii5lCNZM5t9bdoQh4ZnwKsxk/+bd",
      "key_id": "12D5059844B2CD8F",
      "verify": "https://statbook.co.uk/assurance/#verify"
    }
  },
  "figure": {
    "id": "employment.ni.class4.additional_rate",
    "name": "Class 4 National Insurance: additional rate",
    "category": "employment",
    "jurisdiction": "GB",
    "unit": "percent",
    "value_type": "percentage",
    "currency": null,
    "cadence": null,
    "source_type": "act",
    "act_probe": {
      "verdict": "ACT-HOLDS",
      "provision": "section-15-3ZA-b",
      "probed": "2026-07-29",
      "source_url": "https://www.legislation.gov.uk/ukpga/1992/4/section/15/data.xml",
      "content_hash": "sha256:cd8b2efe2ef94e680f9a519fe25821c228d0299e8a319624dee7378021264bb1",
      "tokens": [
        "2%",
        "2 per cent"
      ],
      "commentaries_c": [
        "M_C_29ee241b-c0b2-45d7-b75d-563207f83e97",
        "M_C_57febaab-22a9-41c2-a845-d3c4a418c329",
        "M_C_765458a4-0792-404b-a38f-9278aba0c8dd",
        "M_C_dc9f090e-66ba-430e-d7bc-48de0a25a082",
        "c21367661",
        "key-24f310fd5ace71c88ea238aff4a767de",
        "key-4d73df6b714982f7d8b72be551fe9f5e",
        "key-de98eacd520b446865bb5d7a9b991dd8"
      ],
      "expires": null
    },
    "values": [
      {
        "value": "2%",
        "value_minor": null,
        "effective_from": "2011-04-06",
        "effective_to": null,
        "announcement_date": null,
        "enacted_date": null,
        "instrument_made": true,
        "terminal_kind": null,
        "status": "corroborated",
        "sources": [
          {
            "role": "legislation",
            "citation": "Social Security Contributions and Benefits Act 1992, c. 4 s. 15(3ZA)(b) (\"the additional Class 4 percentage is 2 per cent\")",
            "uri": "https://www.legislation.gov.uk/ukpga/1992/4/section/15",
            "retrieved": "2026-07-29T13:28:36Z",
            "content_hash": "sha256:70bfaaf5415fca7984030bcdfe31c32b6f6ef14664f6ae511128e84c2ea44536"
          },
          {
            "role": "guidance",
            "citation": "https://www.gov.uk/self-employed-national-insurance-rates (Class 4 rates for 2026 to 2027)",
            "uri": "https://www.gov.uk/self-employed-national-insurance-rates",
            "retrieved": "2026-07-29T08:16:12Z",
            "content_hash": "sha256:a1df49d039b43cc6cabc82ee24bc2d9779d910c3fd7a016999bc70db0550bd96"
          }
        ],
        "verified": {
          "guidance": "2026-09-21T10:07:35Z",
          "legislation": "2026-07-29T13:28:36Z"
        },
        "last_verified": "2026-07-29T13:28:36Z"
      }
    ],
    "derivation": null,
    "invariants": [],
    "lineage": [],
    "definitions": [
      {
        "from": null,
        "to": null,
        "text": "The additional Class 4 percentage: the rate of Class 4 National Insurance charged on annual profits from self-employment above the upper profits limit.",
        "instrument": "Social Security Contributions and Benefits Act 1992 s.15(3ZA)(b)"
      }
    ],
    "applicability": {
      "basis": "pay_period_start",
      "note": "Charged on the profits of the tax year, so the rate for the year of assessment governs rather than any payment date.",
      "article": "Social Security Contributions and Benefits Act 1992 s.15(1)-(3ZA)"
    },
    "scope_note": "The alteration power in s.143 of the Social Security Administration Act 1992 is expressed over the MAIN Class 4 percentage; the additional percentage stands in the Act's own words.",
    "notes": "Stated in the spelt form \"2 per cent\" — the same value the employee additional rate carries, but a separate provision for a separate charge, so the two are NOT coupled by an invariant. effective_from is read from the F-note on the archived section: \"Figure in s. 15(3ZA)(b) substituted (6.4.2011) by National Insurance Contributions Act 2011 (c. 3), ss. 2(1)(b), 13(1)\" — a DIFFERENT section of the same 2011 Act from the one that set the employee additional rate, which is why the two rows are dated separately even though both moved that day.",
    "record_version": 3
  },
  "receipt": {
    "record_hash": "sha256:be54158f4e1838c89b4855e737f73e69c2163cd1023c3b770dec9b2679f02b3e",
    "record_hash_of": "the `figure` object, serialized as UTF-8 JSON with 2-space indent, ensure_ascii=false and a trailing newline",
    "release_version": "3.0.0",
    "manifest": "https://statbook.co.uk/v1/releases/3.0.0/manifest.json",
    "record_url": "https://statbook.co.uk/v1/figures/employment.ni.class4.additional_rate.json",
    "sources": [
      {
        "role": "legislation",
        "citation": "Social Security Contributions and Benefits Act 1992, c. 4 s. 15(3ZA)(b) (\"the additional Class 4 percentage is 2 per cent\")",
        "uri": "https://www.legislation.gov.uk/ukpga/1992/4/section/15",
        "retrieved": "2026-07-29T13:28:36Z",
        "content_hash": "sha256:70bfaaf5415fca7984030bcdfe31c32b6f6ef14664f6ae511128e84c2ea44536"
      },
      {
        "role": "guidance",
        "citation": "https://www.gov.uk/self-employed-national-insurance-rates (Class 4 rates for 2026 to 2027)",
        "uri": "https://www.gov.uk/self-employed-national-insurance-rates",
        "retrieved": "2026-07-29T08:16:12Z",
        "content_hash": "sha256:a1df49d039b43cc6cabc82ee24bc2d9779d910c3fd7a016999bc70db0550bd96"
      }
    ],
    "verified": {
      "guidance": "2026-09-21T10:07:35Z",
      "legislation": "2026-07-29T13:28:36Z"
    },
    "last_verified": "2026-07-29T13:28:36Z"
  }
}