Novation of the contract means creating a new contract, while the old one is terminated and does not need to be executed. It is an act that replaces a new obligation or part in a contract with the old one. In addition, the new replaced agreement should be valid and enforceable, taken into account and agreed between the parties. In principle, he should fulfil the conditions of a valid contract. There is an infringement in case of non-compliance with the contractual conditions. At least one party does not hold its part of the agreement. There are different types of offences: the parties are free to conclude a treaty and to modify its terms by mutual agreement. If both parties agree to change the duration of the contract they have previously concluded, the new agreement becomes binding on them. .