# 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-5081-64/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-5081-64/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-5081-64/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 caption: machine translation, not official suppl-5081-64/art-1 · https://japanlaw.org/ja/income-tax-act/suppl-5081-64/art-1 **第一項** この法律は、公布の日から起算して一年を超えない範囲内において政令で定める日から施行する。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。 suppl-5081-64/art-1/par-1 · https://japanlaw.org/ja/income-tax-act/suppl-5081-64/art-1/par-1 This Act comes into effect on the date specified by Cabinet Order within a period not exceeding one year from the date of promulgation; provided, however, that the provisions set forth in the following items come into effect on the dates specified respectively in those items: machine translation, not official **一** 略 suppl-5081-64/art-1/par-1/item-1 · https://japanlaw.org/ja/income-tax-act/suppl-5081-64/art-1/par-1/item-1 Omitted machine translation, not official **二** 第一条中金融商品取引法第百九十七条第一項の改正規定、同法第百九十七条の二第一項の改正規定（同項第一号の改正規定を除く。）及び同法第二百十条第一項の改正規定並びに附則第四十一条、第四十七条及び第八十九条の規定　公布の日から起算して二十日を経過した日 suppl-5081-64/art-1/par-1/item-2 · https://japanlaw.org/ja/income-tax-act/suppl-5081-64/art-1/par-1/item-2 the provisions in Article 1 amending Article 197, paragraph (1) of the Financial Instruments and Exchange Act, amending Article 197-2, paragraph (1) of that Act (excluding the provisions amending item (i) of that paragraph), and amending Article 210, paragraph (1) of that Act, and the provisions of Articles 41, 47, and 89 of the Supplementary Provisions: the day on which 20 days have elapsed from the date of promulgation; machine translation, not official --- ## Cites - suppl-5081-64/art-1/par-1/item-2: 第八十九条 → 所得税法 附則第八十九条 (Supplementary Provisions, Article 89), suppl-5081-64/art-89 — https://japanlaw.org/ja/income-tax-act/suppl-5081-64/art-89 ## Cited by 1 provision cites this one. No official source publishes this direction. - 所得税法 附則第八十九条第一項（罰則に関する経過措置） — https://japanlaw.org/ja/income-tax-act/suppl-5081-64/art-89/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-20260918T174921-140, translated 2026-10-12 - This site's parser, version 225 — 所得税法 — structure, counts, cross-references and defined terms, computed 2026-10-05