# 民法 / Civil Code — 第七百八十六条 (Article 786) - Law: 民法 (Civil Code), 明治二十九年法律第八十九号 - English title "Civil Code": 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: 第七百八十六条 (Article 786)（認知の無効の訴え） — address `art-786` - Text in force since: 2026-06-24 - URL (the page that opens at this provision): https://japanlaw.org/en/civil-code/art-786 - Permanent URL (e-Gov law ID, never renamed): https://japanlaw.org/l/129AC0000000089/art-786 - Every provision below carries its address and both URLs 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. --- ### 第七百八十六条（認知の無効の訴え） — Action to Invalidate an Acknowledgment of Parentage caption: machine translation, not official art-786 · https://japanlaw.org/en/civil-code/art-786 · https://japanlaw.org/l/129AC0000000089/art-786 **第一項** 次の各号に掲げる者は、それぞれ当該各号に定める時（第七百八十三条第一項の規定による認知がされた場合にあっては、子の出生の時）から七年以内に限り、認知について反対の事実があることを理由として、認知の無効の訴えを提起することができる。ただし、第三号に掲げる者について、その認知の無効の主張が子の利益を害することが明らかなときは、この限りでない。 art-786/par-1 · https://japanlaw.org/en/civil-code/art-786/par-1 · https://japanlaw.org/l/129AC0000000089/art-786/par-1 The persons set forth in the following items may file an action to invalidate an acknowledgment of parentage, on the grounds that there are facts contrary to the acknowledgment, only within seven years from the time specified respectively in those items (or, in the case where the acknowledgment was made pursuant to the provisions of Article 783, paragraph (1), the time of the child's birth); provided, however, that this does not apply to the person set forth in item (iii) if it is clear that the assertion of invalidity of the acknowledgment would harm the interests of the child. machine translation, not official **一** 子又はその法定代理人　子又はその法定代理人が認知を知った時 art-786/par-1/item-1 · https://japanlaw.org/en/civil-code/art-786/par-1/item-1 · https://japanlaw.org/l/129AC0000000089/art-786/par-1/item-1 the child or the child's legal representative: the time when the child or the child's legal representative learns of the acknowledgment; machine translation, not official **二** 認知をした者　認知の時 art-786/par-1/item-2 · https://japanlaw.org/en/civil-code/art-786/par-1/item-2 · https://japanlaw.org/l/129AC0000000089/art-786/par-1/item-2 the person who made the acknowledgment: the time of the acknowledgment; machine translation, not official **三** 子の母　子の母が認知を知った時 art-786/par-1/item-3 · https://japanlaw.org/en/civil-code/art-786/par-1/item-3 · https://japanlaw.org/l/129AC0000000089/art-786/par-1/item-3 the child's mother: the time when the child's mother learns of the acknowledgment. machine translation, not official **第二項** 子は、その子を認知した者と認知後に継続して同居した期間（当該期間が二以上あるときは、そのうち最も長い期間）が三年を下回るときは、前項（第一号に係る部分に限る。）の規定にかかわらず、二十一歳に達するまでの間、認知の無効の訴えを提起することができる。ただし、子による認知の無効の主張が認知をした者による養育の状況に照らして認知をした者の利益を著しく害するときは、この限りでない。 art-786/par-2 · https://japanlaw.org/en/civil-code/art-786/par-2 · https://japanlaw.org/l/129AC0000000089/art-786/par-2 If the period during which the child has continuously lived with the person who acknowledged the child after the acknowledgment (or, if there are two or more such periods, the longest of them) is less than three years, the child may, notwithstanding the provisions of the preceding paragraph (limited to the part pertaining to item (i)), file an action to invalidate the acknowledgment of parentage until the child reaches the age of 21; provided, however, that this does not apply if the child's assertion of invalidity of the acknowledgment would significantly harm the interests of the person who made the acknowledgment in light of the circumstances of upbringing by that person. machine translation, not official **第三項** 前項の規定は、同項に規定する子の法定代理人が第一項の認知の無効の訴えを提起する場合には、適用しない。 art-786/par-3 · https://japanlaw.org/en/civil-code/art-786/par-3 · https://japanlaw.org/l/129AC0000000089/art-786/par-3 The provisions of the preceding paragraph do not apply where the legal representative of the child prescribed in that paragraph files the action to invalidate an acknowledgment of parentage under paragraph (1). machine translation, not official **第四項** 第一項及び第二項の規定により認知が無効とされた場合であっても、子は、認知をした者が支出した子の監護に要した費用を償還する義務を負わない。 art-786/par-4 · https://japanlaw.org/en/civil-code/art-786/par-4 · https://japanlaw.org/l/129AC0000000089/art-786/par-4 Even if an acknowledgment is invalidated pursuant to the provisions of paragraphs (1) and (2), the child is not obligated to reimburse the costs required for the custody of the child that were expended by the person who made the acknowledgment. machine translation, not official --- ## Cites - art-786/par-1: 第七百八十三条第一項 → 民法 第七百八十三条第一項 (Article 783, paragraph (1)), art-783/par-1 — https://japanlaw.org/en/civil-code/art-783/par-1 · https://japanlaw.org/l/129AC0000000089/art-783/par-1 - art-786/par-1: 第三号 → 民法 第七百八十六条第一項第三号 (Article 786, paragraph (1), item (iii)), art-786/par-1/item-3 — https://japanlaw.org/en/civil-code/art-786/par-1/item-3 · https://japanlaw.org/l/129AC0000000089/art-786/par-1/item-3 - art-786/par-2: 前項 → 民法 第七百八十六条第一項 (Article 786, paragraph (1)), art-786/par-1 — https://japanlaw.org/en/civil-code/art-786/par-1 · https://japanlaw.org/l/129AC0000000089/art-786/par-1 - art-786/par-2: 第一号 → 民法 第七百八十六条第一項第一号 (Article 786, paragraph (1), item (i)), art-786/par-1/item-1 — https://japanlaw.org/en/civil-code/art-786/par-1/item-1 · https://japanlaw.org/l/129AC0000000089/art-786/par-1/item-1 - art-786/par-3: 前項 → 民法 第七百八十六条第二項 (Article 786, paragraph (2)), art-786/par-2 — https://japanlaw.org/en/civil-code/art-786/par-2 · https://japanlaw.org/l/129AC0000000089/art-786/par-2 - art-786/par-3: 第一項 → 民法 第七百八十六条第一項 (Article 786, paragraph (1)), art-786/par-1 — https://japanlaw.org/en/civil-code/art-786/par-1 · https://japanlaw.org/l/129AC0000000089/art-786/par-1 - art-786/par-4: 第一項 → 民法 第七百八十六条第一項 (Article 786, paragraph (1)), art-786/par-1 — https://japanlaw.org/en/civil-code/art-786/par-1 · https://japanlaw.org/l/129AC0000000089/art-786/par-1 - art-786/par-4: 第二項 → 民法 第七百八十六条第二項 (Article 786, paragraph (2)), art-786/par-2 — https://japanlaw.org/en/civil-code/art-786/par-2 · https://japanlaw.org/l/129AC0000000089/art-786/par-2 ## Cited by 5 provisions cite this one. No official source publishes this direction. - 民法 第七百八十六条第一項（認知の無効の訴え） — https://japanlaw.org/en/civil-code/art-786/par-1 · https://japanlaw.org/l/129AC0000000089/art-786/par-1 - 民法 第七百八十六条第二項（認知の無効の訴え） — https://japanlaw.org/en/civil-code/art-786/par-2 · https://japanlaw.org/l/129AC0000000089/art-786/par-2 - 民法 第七百八十六条第三項（認知の無効の訴え） — https://japanlaw.org/en/civil-code/art-786/par-3 · https://japanlaw.org/l/129AC0000000089/art-786/par-3 - 民法 第七百八十六条第四項（認知の無効の訴え） — https://japanlaw.org/en/civil-code/art-786/par-4 · https://japanlaw.org/l/129AC0000000089/art-786/par-4 - 民法 附則第五条第二項（胎児の認知及び認知の無効に関する経過措置） — https://japanlaw.org/en/civil-code/suppl-5041-102/art-5/par-2 · https://japanlaw.org/l/129AC0000000089/suppl-5041-102/art-5/par-2 --- ## Sources - e-Gov 法令検索, Digital Agency (デジタル庁) — 民法 — the text in force from 2026-06-24 (https://laws.e-gov.go.jp/law/129AC0000000089/20260624_508AC0000000045), retrieved 2026-10-11 - Japanese Law Translation Database System, Ministry of Justice (法務省) — Civil Code — Ministry of Justice translation (part 1 of 2) (https://www.japaneselawtranslation.go.jp/en/laws/view/4848/tb), retrieved 2026-10-11 - claude-sonnet-5-5 — Machine translation, batch civil-code-20261011T170941-003, translated 2026-10-12 - This site's parser, version 190 — 民法 — structure, counts, cross-references and defined terms, computed 2026-10-11