Validation of marriage or convalidation of marriage is, in Roman Catholic canon law, making a putative marriage a valid one, after the removal of an impediment, or its dispensation, or the removal of defective consent. Once a putative marriage has been validated, it cannot be annulled.
If the impediment to the marriage was a defective consent in one or both parties, a simple renewal of consent can effect validation.
When, however, matrimony is invalid because of a diriment impediment, it may be revalidated by simple dispensation or by that known as Sanatio in Radice.
For a simple dispensation, the couple, having received the dispensation, may validate the marriage by a simple renewal of consent. When the impediment had affected only one of the parties and the other was unaware of the impediment, it is probable that both must renew their consent. That a true renovation of consent be obtained, the parties should be made aware of the nullity of their marriage, unless sanatio in radice be resorted to. The renovation must be made before the authorized ecclesiastical authority and witnesses when the impediment has been public.
The dispensation called sanatio in radice consists in the revalidation of a marriage by reason of a consent formerly given, but ineffective because of an impediment. When the impediment is removed, the consent is ipso facto ratified and no renovation is required. In such a case, it is requisite that the consent of both parties to the marriage had not ceased and that their wedlock had had the external appearance of a true marriage. Sanatio is resorted to when there is urgent reason for not acquainting the parties with the nullity of their marriage, or when one of the parties alone is cognizant of the impediment and the other cannot be informed without grave consequences, or when one party would be unwilling formally to renew a consent that is presumably existent.
The pope has power to give the dispensation called sanatio in radice. Bishops generally have no such power, even when by particular indult they can dispense in diriment impediments. For the granting of sanatio in radice a special apostolic faculty is required. In the United States, the ordinaries may grant such dispensation, under certain limitations, when only one of the parties to the marriage is aware of the impediment.
This article incorporates text from a publication now in the public domain: Herbermann, Charles, ed (1913). "Validation of Marriage". Catholic Encyclopedia. Robert Appleton Company.