The Power of "Carta Registada"

In Portugal, email is often ignored for legal matters. To cancel a contract (gym, internet, rent) or send a formal complaint, you must use "Carta Registada com Aviso de Receção" (Registered Mail with Return Receipt).

The signed receipt you get back is your legal proof that the entity received your request on a specific date. Without this little yellow card, companies can claim they never received your cancellation notice.