# Changes to Japanese law on 1 December 2025

This is the Markdown twin of https://japanlaw.org/en/changes/2025-12-01. 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.

What changed on 1 December 2025 in 6 laws on this site: for each, the Act that amends it.

- Residential Basic Book Act (住民基本台帳法) — https://japanlaw.org/en/residential-basic-book-act
  - Amended by Act on the Development of Related Acts for the Promotion of Reform to Enhance Regional Autonomy and Independence (Act No. 35 of 2025) (地域の自主性及び自立性を高めるための改革の推進を図るための関係法律の整備に関する法律)
    The Act, and every law here it amends: https://japanlaw.org/en/acts/507AC0000000035 (as Markdown: https://japanlaw.org/md/en/acts/507AC0000000035)
    Listed with the law's amendments: https://japanlaw.org/en/residential-basic-book-act/amendments; the text on e-Gov: https://laws.e-gov.go.jp/law/342AC0000000081/20251201_507AC0000000035
- Employees' Pension Insurance Act (厚生年金保険法) — https://japanlaw.org/en/employees-pension-insurance-act
  - Amended by Act Partially Amending the National Pension Act, etc., and Other Matters, to Strengthen the Functions of the Pension System in Light of Socioeconomic Changes (Act No. 74 of 2025) (社会経済の変化を踏まえた年金制度の機能強化のための国民年金法等の一部を改正する等の法律)
    The Act, and every law here it amends: https://japanlaw.org/en/acts/507AC0000000074 (as Markdown: https://japanlaw.org/md/en/acts/507AC0000000074)
    Listed with the law's amendments: https://japanlaw.org/en/employees-pension-insurance-act/amendments; the text on e-Gov: https://laws.e-gov.go.jp/law/329AC0000000115/20251201_507AC0000000074
- National Pension Act (国民年金法) — https://japanlaw.org/en/national-pension-act
  - Amended by Act Partially Amending the National Pension Act, etc., and Other Matters, to Strengthen the Functions of the Pension System in Light of Socioeconomic Changes (Act No. 74 of 2025) (社会経済の変化を踏まえた年金制度の機能強化のための国民年金法等の一部を改正する等の法律)
    The Act, and every law here it amends: https://japanlaw.org/en/acts/507AC0000000074 (as Markdown: https://japanlaw.org/md/en/acts/507AC0000000074)
    Listed with the law's amendments: https://japanlaw.org/en/national-pension-act/amendments; the text on e-Gov: https://laws.e-gov.go.jp/law/334AC0000000141/20251201_507AC0000000074
- Income Tax Act (所得税法) — https://japanlaw.org/en/income-tax-act
  - Amended by Act Partially Amending the Income Tax Act, etc. (Act No. 13 of 2025) (所得税法等の一部を改正する法律)
    The Act, and every law here it amends: https://japanlaw.org/en/acts/507AC0000000013 (as Markdown: https://japanlaw.org/md/en/acts/507AC0000000013)
    Listed with the law's amendments: https://japanlaw.org/en/income-tax-act/amendments; the text on e-Gov: https://laws.e-gov.go.jp/law/340AC0000000033/20251201_507AC0000000013
- Regulation for Enforcement of the Income Tax Act (所得税法施行規則) — https://japanlaw.org/en/income-tax-act-enforcement-regulation
  - Amended by Ministerial Order Partially Amending the Regulation for Enforcement of the Income Tax Act (Ministry of Finance Order No. 18 of 2025) (所得税法施行規則の一部を改正する省令)
    The Act, and every law here it amends: https://japanlaw.org/en/acts/507M60000040018 (as Markdown: https://japanlaw.org/md/en/acts/507M60000040018)
    Listed with the law's amendments: https://japanlaw.org/en/income-tax-act-enforcement-regulation/amendments; the text on e-Gov: https://laws.e-gov.go.jp/law/340M50000040011/20251201_507M60000040018
- Act on Special Measures Concerning Taxation (租税特別措置法) — https://japanlaw.org/en/special-taxation-measures-act
  - Amended by Act Partially Amending the Income Tax Act, etc. (Act No. 13 of 2025) (所得税法等の一部を改正する法律)
    The Act, and every law here it amends: https://japanlaw.org/en/acts/507AC0000000013 (as Markdown: https://japanlaw.org/md/en/acts/507AC0000000013)
    Listed with the law's amendments: https://japanlaw.org/en/special-taxation-measures-act/amendments; the text on e-Gov: https://laws.e-gov.go.jp/law/332AC0000000026/20251201_507AC0000000013

Every day: https://japanlaw.org/en/changes

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## Sources

- Amendments and their dates: e-Gov (Digital Agency) (6 records)
- English names of the laws: Japanese Law Translation, Ministry of Justice (6 records)
- English titles of the amending laws: Written for this site with AI