Contrary to popular belief, one cannot annul a marriage in Oklahoma just because the marriage lasted only a few weeks or months. Failure to consummate a marriage sexually is also not grounds, by itself, to annul a marriage. Annulment has to do with the capacity of the parties to enter into the marriage contract, and good faith dealing between the parties. In Oklahoma, marriage is defined as a "personal relation" arising out of a "civil contract." Dissolution of marriage (divorce) terminates the marriage contract. Annulment sets aside the marriage contract as though it never existed.

A marriage can be annulled for any of the reasons that a contract can be set aside. For example, persons who are under legal age or lack the mental capacity to marry can have their marriage annulled. A marriage can be annulled for fraud. However, buyer's remorse and absence of intimate relations by themselves are not grounds to annul a marriage.