generalLatin origin
Ab Initio
/ab ih-NIH-shee-oh/
From the beginning — a legal act that is void from its very inception, as if it never existed.
Full Definition
Ab initio (Latin: 'from the beginning') means from the very start. A contract void ab initio is treated as never formed. A marriage void ab initio is treated as never having taken place. A law declared unconstitutional is void ab initio and all actions under it are invalid.
In Indian Law
Under Article 13(2), laws infringing fundamental rights are void ab initio. Section 11 Hindu Marriage Act declares bigamous, prohibited-degree, and underage marriages void ab initio. Contrast with voidable marriages (Section 12) which are valid until annulled.