My ex-wife and I are reconciling. Can our marriage annulment be reversed?
No, an annulment cannot be reversed unless the grounds that were the basis for the decree of nullity are demonstrably shown to be false.
In order to issue a decree of nullity, the tribunal judges must reach moral certainty that an essential element to the consent of marriage was missing. Moral certainty is more than a judgment of probability, personal weighing of facts, and is more than even beyond a reasonable doubt. Moral certainty means that enough evidence was provided that the tribunal judges have no other conclusion that can be reached.
The moral certainty in question in this process should be understood to mean the judge’s state of mind, his conviction, and his firm adherence to the truth, made known and proven in the trial, concerning the existence of factors that already invalidated the marriage at the moment of its celebration.
It is not, therefore, a matter of an absolute certainty, in which every possible doubt about the truth of the facts to be judged is totally excluded, nor is it a purely subjective certainty based on personal opinion, sentiment or an impression of the cause; rather, it is a matter of an objective moral certitude, objectively founded on those things [ex actis] which have been carried out and proven in the process (cf. art. 247 3).
If you reconcile with your ex and wish to marry, you will be asked to exchange vows.