(1) On fulfilment of a resolutive condition, the rules on restitution set out in Articles 7.3.6 and 7.3.7 apply with appropriate adaptations.
(2) If the parties have agreed that the resolutive condition is to operate retroactively, the rules on restitution set out in Article 3.2.15 apply with appropriate adaptations.
When a contract subject to a resolutive condition comes to an end as a result of the fulfilment of the resolutive condition, the parties will often have performed, fully or in part, their obligations under the contract. The question then arises whether and, if so, under which rules, the parties have to make restitution of what they have received.
Under the Principles, the fulfilment of a resolutive condition normally has prospective effects only. For this reason restitution will have to follow the regime set out in Articles 7.3.6 and 7.3.7 on restitution following the termination of a contract, which also operates only prospectively. The specificity of this restitution regime vis-à-vis the restitution regime set out in Article 3.2.15 is that for contracts to be performed over a period of time, restitution cannot be claimed for the period prior to the moment when the contract came to an end.
However, under the Principles parties are free to determine that a resolutive condition is to operate retroactively. Under these circumstances it appears to be appropriate to apply the restitution regime set out in Article 3.2.15 (restitution following avoidance) since avoidance also operates retroactively. There is no special rule for restitution in the case of contracts performed over a period of time.