contract and returns the parties to the position they were in before contracting, known as retroactive effect. Each party must return what it received: the buyer recovers the price and the seller takes back the goods. This rule does not change merely because termination was carried out electronically, since the means used does not alter the legal nature of the effect, provided the formal and evidentiary requirements are met. However, retroactive effect does not apply to every contract. In instantaneous contracts, such as the sale of a digital product, it applies in full. In continuing contracts, such as subscriptions, hosting, and software services, termination operates only prospectively. Installments due and services already performed before termination remain payable and count as acquired rights that termination does not erase. Electronic termination brings several considerations to the fore. First is timing: the termination usually takes effect when the electronic notice reaches the other party, not when it is sent, and deadlines and obligations are calculated accordingly. Second is evidence: digital messages and records carry probative weight when a reliable electronic signature and the integrity of the record can be shown, and the injured party keeps the right to claim compensation for the breach that caused the termination. Third are penalty clauses: they remain enforceable if they fell due before termination, though courts retain the power to reduce them if excessive. Fourth is consumer protection: e-commerce legislation typically grants consumers a withdrawal right within a set period without giving reasons, with a refund of what they paid, an exception that balances an unequal relationship. Fifth is personal data: once the contract ends, the counterparty must stop processing or delete the data, except what the law requires it to retain.