Restitutio in integrum

The parties to a transaction may do things in the belief that the transaction is legally valid, whereas in fact it is void, or it is set aside as void by a court. In these circumstances, it follows that anything done in reliance on the validity of the transaction must be reversed. This process of reversal is what is known as 'restitutio in integrum'. The parties to the transaction must restore anything received, and not retain any benefit they would not have had in the absence of a valid transaction.