An annulment is a declaration by a Church tribunal (a Catholic church court) that a marriage thought to be valid according to Church law actually fell short of at least one of the essential elements required for a binding union.

An annulment is concerned mainly with the personal and spiritual aspects of marriage. It does not erase the civil contract, and it does not render the children illegitimate. It merely states that after thorough investigation, the Church has decided that a marriage, as the Church understands marriage, was not valid.