Wikipedia
A putative marriage is an apparently valid marriage, entered into in good faith on the part of at least one of the partners, but that is legally invalid due to a technical impediment, such as a preexistent marriage on the part of one of the partners. Unlike someone in a common-law, statutory, or ceremonial marriage, a putative spouse is not legally married. Instead, a putative spouse believes himself or herself to be married in good faith and is given legal rights as a result of this person's reliance upon this good-faith belief.
Putative marriages exist in both Catholic canon law and in various civil laws, though the rules may vary. In some jurisdictions, putative marriages are a matter of case law rather than legislation. In many jurisdictions, under civil law, the marriage becomes valid if the impediment is removed. If it is not removed, the innocent spouse, at least, is often entitled to the protections of a divorce for division of property and child custody.