Although a contract signed by both parties is apparently valid and mandatory for both sides, there may be exceptional circumstances enabling resolution:
Contracts with abusive clauses:There are contracts with abusive clauses –either one, several or all-. Unfair terms are those which, being contrary to good faith and fair balance between the rights and obligations of the parties (consumer and professional) produce consequences as limiting consumer rights, imposing disproportionate obligations or guarantees, linking the contract to the will the other party, etc. Unfair terms are therefore automatically null and void and will be taken as not placed. In the event that the remaining clauses (those that are not abusive) determine an inequitable situation in the position of the parties that cannot be remedied, the contract can then be declared ineffective.
Contracts signed under coercion, intimidation or violence: The law states that one of the prerequisites for the development of a contract is the consent of the parties, that is, the will to want obligating, so that if it is forced to sign something had not wanted freely, the contract will be void.
Unfulfilled contracts:Resolution (cancellation) is a remedy which the law allows use when there is a perfect contract and this is then disobeyed because a befallen event or behaviour of the counterparty has altered the relationships created originally, so that the content and interest inherent in the contract have been left unprotected and unfulfilled and therefore leaves an injurious condition on one of the parties.