The main text is read a page at a time: a chapter to a page, and a long chapter in runs of articles. The whole main text, and the supplementary provisions and appended tables this amendment changes. Those it leaves untouched are on the page for the text in force.
The provisions of Article 23, paragraph (1) of the New Act (limited to the part relating to items (vii) and (ix)) apply from individual prefectural inhabitant tax for fiscal year 2027, and the provisions then in force continue to govern individual prefectural inhabitant tax up to fiscal year 2026.
The provisions of Article 37-2, paragraph (11) and Article 5-5, paragraph (1) of the Supplementary Provisions of the Local Tax Act as amended by the provisions set forth in Article 1, item (ii) of the Supplementary Provisions (referred to as the "January 2027 New Act" in paragraph (12) and Article 11, paragraphs (8) and (10) of the Supplementary Provisions) apply from individual prefectural inhabitant tax for fiscal year 2028, and the provisions then in force continue to govern individual prefectural inhabitant tax up to fiscal year 2027.
The provisions of Article 45-3-3, paragraphs (1) and (2) of the New Act apply to a return under Article 45-3-3, paragraph (1) of the New Act that is submitted with regard to public pensions, etc. (meaning public pensions, etc. prescribed in Article 203-6, paragraph (1) of the Income Tax Act (Act No. 33 of 1965); hereinafter in this paragraph and Article 11, paragraph (9) of the Supplementary Provisions referred to as "public pensions, etc.") that are to be paid on or after the date of enforcement of the provisions set forth in Article 1, item (ii) of the Supplementary Provisions (hereinafter in this paragraph and Article 11, paragraph (9) of the Supplementary Provisions referred to as the "Item 2 Effective Date"), and the provisions then in force continue to govern a return under Article 45-3-3, paragraph (1) of the Former Act that was submitted with regard to public pensions, etc. that were to be paid before the Item 2 Effective Date.
The provisions of Article 5-4, paragraphs (1) through (4) of the Supplementary Provisions of the January 2027 New Act apply where a person liable for tax for the income levy of prefectural inhabitant tax, on or after January 1, 2026, uses as their residence, as provided in Article 41, paragraph (1) of the Act on Special Measures Concerning Taxation (Act No. 26 of 1957; referred to as the "New Act on Special Measures Concerning Taxation" in the following Article, Article 5 of the Supplementary Provisions and Articles 11 through 13 of the Supplementary Provisions) as amended by the provisions of Article 7 of the Act Partially Amending the Income Tax Act, etc. (Act No. 12 of 2026; hereinafter in this paragraph, paragraph (18) and Article 11, paragraph (15) of the Supplementary Provisions referred to as the "Income Tax Act Amendment Act"), a residential house prescribed in that paragraph (including a dwelling eligible for the special measure prescribed in paragraph (16) of that Article that is deemed to be a residential house prescribed in paragraph (1) of that Article pursuant to paragraph (16) of that Article), an existing house (including a special-case existing house prescribed in paragraph (17) of that Article that is deemed to be an existing house prescribed in paragraph (1) of that Article pursuant to paragraph (17) of that Article and a house requiring seismic retrofitting prescribed in paragraph (35) of that Article that is deemed to be an existing house prescribed in paragraph (1) of that Article pursuant to paragraph (35) of that Article), a house that has undergone extension, rebuilding, etc. (including a house that has undergone special-case extension, rebuilding, etc. prescribed in paragraph (17) of that Article that is deemed to be a house that has undergone extension, rebuilding, etc. prescribed in paragraph (1) of that Article pursuant to paragraph (17) of that Article, and limited to the part pertaining to that extension, rebuilding, etc. or that special-case extension, rebuilding, etc.), or a certified house, etc. prescribed in paragraph (6) of that Article (including a special-case certified house, etc. prescribed in paragraph (18) of that Article that is deemed to be a certified house, etc. prescribed in paragraph (6) of that Article pursuant to paragraph (18) of that Article), and the provisions then in force continue to govern where a person liable for tax for the income levy of prefectural inhabitant tax, before that date, used as their residence, as provided in Article 41, paragraph (1) of the Act on Special Measures Concerning Taxation prior to amendment by the provisions of Article 7 of the Income Tax Act Amendment Act (referred to as the "Former Act on Special Measures Concerning Taxation" in paragraph (18) and Article 11, paragraphs (10) and (15) of the Supplementary Provisions), a residential house prescribed in that paragraph (including a dwelling eligible for the special measure prescribed in paragraph (20) of that Article that is deemed to be a residential house prescribed in paragraph (1) of that Article pursuant to paragraph (20) of that Article), an existing house (including a house requiring seismic retrofitting prescribed in paragraph (35) of that Article that is deemed to be an existing house prescribed in paragraph (1) of that Article pursuant to paragraph (35) of that Article), a house that has undergone extension, rebuilding, etc. (limited to the part pertaining to that extension, rebuilding, etc.), or a certified house, etc. prescribed in paragraph (10) of that Article (including a special-case certified house, etc. prescribed in paragraph (21) of that Article that is deemed to be a certified house, etc. prescribed in paragraph (10) of that Article pursuant to paragraph (21) of that Article).
The provisions of Article 292, paragraph (1) of the New Act (limited to the part pertaining to items (vii) and (ix)) apply to individual municipal inhabitant tax for fiscal 2027 and subsequent fiscal years, and the provisions then in force continue to govern individual municipal inhabitant tax through fiscal 2026.
The provisions of Article 314-7, paragraph (11) of the January 2027 New Act and Article 5-5, paragraph (2) of the Supplementary Provisions of the January 2027 New Act apply to individual municipal inhabitant tax for fiscal 2028 and subsequent fiscal years, and the provisions then in force continue to govern individual municipal inhabitant tax through fiscal 2027.
The provisions of Article 317-3-3, paragraphs (1) and (2) of the New Act apply to the return under paragraph (1) of that Article submitted with respect to public pensions, etc. to be received on or after the Item 2 Effective Date, and the provisions then in force continue to govern the return under Article 317-3-3, paragraph (1) of the Former Act submitted with respect to public pensions, etc. to be received before the Item 2 Effective Date.
The provisions of Article 5-4, paragraphs (5) through (8) of the Supplementary Provisions of the January 2027 New Act apply where a person liable for tax for the income levy of municipal inhabitant tax, on or after January 1, 2026, uses as their residence, as provided in Article 41, paragraph (1) of the New Act on Special Measures Concerning Taxation, a residential house prescribed in that paragraph (including a dwelling eligible for the special measure prescribed in paragraph (16) of that Article that is deemed to be a residential house prescribed in paragraph (1) of that Article pursuant to paragraph (16) of that Article), an existing house (including a special-case existing house prescribed in paragraph (17) of that Article that is deemed to be an existing house prescribed in paragraph (1) of that Article pursuant to paragraph (17) of that Article and a house requiring seismic retrofitting prescribed in paragraph (35) of that Article that is deemed to be an existing house prescribed in paragraph (1) of that Article pursuant to paragraph (35) of that Article), a house that has undergone extension, rebuilding, etc. (including a house that has undergone special-case extension, rebuilding, etc. prescribed in paragraph (17) of that Article that is deemed to be a house that has undergone extension, rebuilding, etc. prescribed in paragraph (1) of that Article pursuant to paragraph (17) of that Article, and limited to the part pertaining to that extension, rebuilding, etc. or that special-case extension, rebuilding, etc.), or a certified house, etc. prescribed in paragraph (6) of that Article (including a special-case certified house, etc. prescribed in paragraph (18) of that Article that is deemed to be a certified house, etc. prescribed in paragraph (6) of that Article pursuant to paragraph (18) of that Article), and the provisions then in force continue to govern where a person liable for tax for the income levy of municipal inhabitant tax, before that date, used as their residence, as provided in Article 41, paragraph (1) of the Former Act on Special Measures Concerning Taxation, a residential house prescribed in that paragraph (including a dwelling eligible for the special measure prescribed in paragraph (20) of that Article that is deemed to be a residential house prescribed in paragraph (1) of that Article pursuant to paragraph (20) of that Article), an existing house (including a house requiring seismic retrofitting prescribed in paragraph (35) of that Article that is deemed to be an existing house prescribed in paragraph (1) of that Article pursuant to paragraph (35) of that Article), a house that has undergone extension, rebuilding, etc. (limited to the part pertaining to that extension, rebuilding, etc.), or a certified house, etc. prescribed in paragraph (10) of that Article (including a special-case certified house, etc. prescribed in paragraph (21) of that Article that is deemed to be a certified house, etc. prescribed in paragraph (10) of that Article pursuant to paragraph (21) of that Article).
The day a law or an amendment starts to apply. It is often months or years after promulgation, so that people have time to prepare. The Ministry of Justice's English usually says a law "comes into force" or "comes into effect", and sometimes calls the day its "enforcement date". Its "enforcement" more often means the word's other sense, carrying a law out, as in an Order for Enforcement (施行令), the Cabinet Order (政令) that sets out the details for carrying out an Act.