# 所得税法 / Income Tax Act — 附　則 (Supplementary Provisions)

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- 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: 附　則 (Supplementary Provisions) — address `suppl-4121-23`
- Text in force since: 2026-10-01
- URL (the page that opens at this provision): https://japanlaw.org/ja/income-tax-act/suppl-4121-23
- 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.

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## 附　則 平成一二年三月三一日法律第二三号
<sup>suppl-4121-23 · https://japanlaw.org/ja/income-tax-act/suppl-4121-23</sup>

### 第一条（施行期日） — Effective Date
<sup>caption: machine translation, not official</sup>
<sup>suppl-4121-23/art-1 · https://japanlaw.org/ja/income-tax-act/suppl-4121-23/art-1</sup>

**第一項**  この法律は、平成十二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-4121-23/art-1/par-1 · https://japanlaw.org/ja/income-tax-act/suppl-4121-23/art-1/par-1</sup>
This Act comes into effect on April 1, 2000; provided, however, that the provisions set forth in the following items come into effect on the dates specified respectively in those items:
<sup>machine translation, not official</sup>

  **一及び二**  略
  <sup>suppl-4121-23/art-1/par-1/item-1-to-2 · https://japanlaw.org/ja/income-tax-act/suppl-4121-23/art-1/par-1/item-1-to-2</sup>
  Omitted
  <sup>machine translation, not official</sup>

  **三**  第二条（次号に掲げる改正規定を除く。）、第四条及び第五条並びに附則第七条から第十条までの規定　平成十五年四月一日
  <sup>suppl-4121-23/art-1/par-1/item-3 · https://japanlaw.org/ja/income-tax-act/suppl-4121-23/art-1/par-1/item-3</sup>
  the provisions of Article 2 (excluding the amending provisions set forth in the following item), Article 4, and Article 5, and the provisions of Articles 7 through 10 of the Supplementary Provisions: April 1, 2003;
  <sup>machine translation, not official</sup>

### 第十条（所得税法の一部改正に伴う経過措置） — Transitional Measures Accompanying the Partial Amendment of the Income Tax Act
<sup>caption: machine translation, not official</sup>
<sup>suppl-4121-23/art-10 · https://japanlaw.org/ja/income-tax-act/suppl-4121-23/art-10</sup>

**第一項**  第二条の規定による改正前の私立学校教職員共済法第三十四条の二第五項において準用する同法第二十八条第一項の規定により加入者として負担した特別掛金は、前条の規定による改正後の所得税法第七十四条第二項第十一号の社会保険料とみなして、同法の規定を適用する。
<sup>suppl-4121-23/art-10/par-1 · https://japanlaw.org/ja/income-tax-act/suppl-4121-23/art-10/par-1</sup>
Special installments borne as a member pursuant to the provisions of Article 28, paragraph (1) of the Private School Personnel Mutual Aid Association Act as applied mutatis mutandis pursuant to Article 34-2, paragraph (5) of that Act prior to amendment by the provisions of Article 2 are deemed to be social insurance premiums under Article 74, paragraph (2), item (xi) of the Income Tax Act as amended by the provisions of the preceding Article, and the provisions of that Act apply.
<sup>machine translation, not official</sup>

### 第十一条（その他の経過措置の政令への委任） — Delegation of Other Transitional Measures to Cabinet Order
<sup>caption: machine translation, not official</sup>
<sup>suppl-4121-23/art-11 · https://japanlaw.org/ja/income-tax-act/suppl-4121-23/art-11</sup>

**第一項**  この附則に規定するもののほか、この法律の施行に伴い必要な経過措置は、政令で定める。
<sup>suppl-4121-23/art-11/par-1 · https://japanlaw.org/ja/income-tax-act/suppl-4121-23/art-11/par-1</sup>
Beyond what is provided for in these Supplementary Provisions, transitional measures necessary in connection with the enforcement of this Act are specified by Cabinet Order.
<sup>machine translation, not official</sup>

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## Cites
- suppl-4121-23/art-1/par-1/item-3: 附則第七条から第十条まで → 所得税法 附則第十条 (Supplementary Provisions, Article 10), suppl-4121-23/art-10 — https://japanlaw.org/ja/income-tax-act/suppl-4121-23/art-10
- suppl-4121-23/art-10/par-1: 所得税法第七十四条第二項第十一号 → 所得税法 第七十四条第二項第十一号 (Article 74, paragraph (2), item (xi)), art-74/par-2/item-11 — https://japanlaw.org/ja/income-tax-act/art-74/par-2/item-11

## Cited by

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

- 所得税法 附則第一条第一項第三号（施行期日） — https://japanlaw.org/ja/income-tax-act/suppl-4121-23/art-1/par-1/item-3

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## 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-20260918T180319-084, translated 2026-09-18
- claude-opus-5[1m] — Machine translation, batch income-tax-act-20260918T180319-085, 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