# 所得税法 / Income Tax Act — 第一条 (Supplementary Provisions, Article 1)

This is the Markdown twin of https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1. Every law, and how to address a provision: https://japanlaw.org/llms.txt. The same laws as MCP tools (no sign-in): https://japanlaw.org/mcp.

- Law: 所得税法 (Income Tax Act), 昭和四十年法律第三十三号
- English title "Income Tax Act": Ministry of Justice translation
- Kind: Act — the distinction between 法律 (Act), 政令 (Cabinet Order), 省令 (Ministerial Order) and 条例 (local ordinance) decides who may issue it and what it may say.
- Provision: 第一条 (Supplementary Provisions, Article 1)（施行期日） — address `suppl-5041-4/art-1`
- Text in force since: 2026-10-01
- URL (the page that opens at this provision): https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1
- e-Gov law ID: 340AC0000000033 — never renamed. A permanent link, `/l/{lawId}/{address}` on this site, redirects to the page.
- Every provision below carries its address and its URL on the line under it.
- Japanese text: e-Gov 法令検索, Digital Agency (デジタル庁). English: as marked on each line below.

Only the Japanese as published by the government has legal effect; the text
below is a copy of it. Every English rendering below is a translation and
says which kind: the Ministry of Justice's translation, or this
site's machine translation, whose model and date the Sources list names.
They are never merged and never substituted for one another.

---

### 第一条（施行期日） — Effective Date
<sup>caption: machine translation, not official</sup>
<sup>suppl-5041-4/art-1 · https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1</sup>

**第一項**  この法律は、令和四年四月一日から施行する。ただし、次の各号に掲げる規定は、当該各号に定める日から施行する。
<sup>suppl-5041-4/art-1/par-1 · https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1/par-1</sup>
This Act comes into effect on April 1, 2022; provided, however, that the provisions set forth in the following items come into effect on the dates specified in those items:
<sup>machine translation, not official</sup>

  **一**  次に掲げる規定　令和四年十月一日
  <sup>suppl-5041-4/art-1/par-1/item-1 · https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1/par-1/item-1</sup>
  the following provisions: October 1, 2022;
  <sup>machine translation, not official</sup>

    **イ**  第一条中所得税法第百九十八条第五項の改正規定及び附則第七条の規定
    <sup>suppl-5041-4/art-1/par-1/item-1/sub-1 · https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1/par-1/item-1/sub-1</sup>
    the provision of Article 1 amending Article 198, paragraph (5) of the Income Tax Act, and the provisions of Article 7 of the Supplementary Provisions;
    <sup>machine translation, not official</sup>

  **二**  略
  <sup>suppl-5041-4/art-1/par-1/item-2 · https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1/par-1/item-2</sup>
  Omitted
  <sup>machine translation, not official</sup>

  **三**  次に掲げる規定　令和五年一月一日
  <sup>suppl-5041-4/art-1/par-1/item-3 · https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1/par-1/item-3</sup>
  the following provisions: January 1, 2023;
  <sup>machine translation, not official</sup>

    **イ**  第一条中所得税法第十六条の改正規定、同法第二十条の改正規定及び同法第四十五条の改正規定並びに次条並びに附則第三条、第五条、第七十九条（地価税法（平成三年法律第六十九号）第三十一条第二項第二号の改正規定を除く。）及び第八十一条から第八十三条までの規定
    <sup>suppl-5041-4/art-1/par-1/item-3/sub-1 · https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1/par-1/item-3/sub-1</sup>
    the provision of Article 1 amending Article 16 of the Income Tax Act, the provision amending Article 20 of that Act and the provision amending Article 45 of that Act, and the provisions of the following Article and of Article 3, Article 5, Article 79 (excluding the provision amending Article 31, paragraph (2), item (ii) of the Land-holding Tax Act (Act No. 69 of 1991)) and Articles 81 through 83 of the Supplementary Provisions;
    <sup>machine translation, not official</sup>

  **四**  略
  <sup>suppl-5041-4/art-1/par-1/item-4 · https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1/par-1/item-4</sup>
  Omitted
  <sup>machine translation, not official</sup>

  **五**  次に掲げる規定　令和五年十月一日
  <sup>suppl-5041-4/art-1/par-1/item-5 · https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1/par-1/item-5</sup>
  the following provisions: October 1, 2023;
  <sup>machine translation, not official</sup>

    **イ**  第一条中所得税法第百七十七条の改正規定及び同法第二百十二条の改正規定並びに附則第六条及び第八条の規定
    <sup>suppl-5041-4/art-1/par-1/item-5/sub-1 · https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1/par-1/item-5/sub-1</sup>
    the provision of Article 1 amending Article 177 of the Income Tax Act and the provision amending Article 212 of that Act, and the provisions of Articles 6 and 8 of the Supplementary Provisions;
    <sup>machine translation, not official</sup>

  **六**  次に掲げる規定　令和六年一月一日
  <sup>suppl-5041-4/art-1/par-1/item-6 · https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1/par-1/item-6</sup>
  the following provisions: January 1, 2024;
  <sup>machine translation, not official</sup>

    **イ**  第一条中所得税法第百五十一条の四第四項第二号の改正規定
    <sup>suppl-5041-4/art-1/par-1/item-6/sub-1 · https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-1/par-1/item-6/sub-1</sup>
    the provision of Article 1 amending Article 151-4, paragraph (4), item (ii) of the Income Tax Act.
    <sup>machine translation, not official</sup>

---

## Cites
- suppl-5041-4/art-1/par-1/item-1/sub-1: 附則第七条 → 所得税法 附則第七条 (Supplementary Provisions, Article 7), suppl-5041-4/art-7 — https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-7
- suppl-5041-4/art-1/par-1/item-3/sub-1: 次条 → 所得税法 附則第二条 (Supplementary Provisions, Article 2), suppl-5041-4/art-2 — https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-2
- suppl-5041-4/art-1/par-1/item-3/sub-1: 附則第三条 → 所得税法 附則第三条 (Supplementary Provisions, Article 3), suppl-5041-4/art-3 — https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-3
- suppl-5041-4/art-1/par-1/item-3/sub-1: 第五条 → 所得税法 附則第五条 (Supplementary Provisions, Article 5), suppl-5041-4/art-5 — https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-5
- suppl-5041-4/art-1/par-1/item-5/sub-1: 附則第六条 → 所得税法 附則第六条 (Supplementary Provisions, Article 6), suppl-5041-4/art-6 — https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-6
- suppl-5041-4/art-1/par-1/item-5/sub-1: 第八条 → 所得税法 附則第八条 (Supplementary Provisions, Article 8), suppl-5041-4/art-8 — https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-8

## Cited by

1 provision cites this one. No official source publishes this direction.

- 所得税法 附則第九十八条第一項（罰則に関する経過措置） — https://japanlaw.org/ja/income-tax-act/suppl-5041-4/art-98/par-1

---

## Sources

- e-Gov 法令検索, Digital Agency (デジタル庁) — 所得税法 — the text in force from 2026-10-01 (https://laws.e-gov.go.jp/law/340AC0000000033/20261001_507AC0000000070), retrieved 2026-10-05
- Japanese Law Translation Database System, Ministry of Justice (法務省) — Income Tax Act — Ministry of Justice translation (https://www.japaneselawtranslation.go.jp/en/laws/view/3120/tb), retrieved 2026-09-18
- claude-opus-5[1m] — Machine translation, batch income-tax-act-20260918T180319-131, translated 2026-09-18
- This site's parser, version 224 — 所得税法 — structure, counts, cross-references and defined terms, computed 2026-10-05