The Rome I Regulation is the starting point for determining conflict of law rules for contractual obligations. The basic rule on which the regulation is based is the principle of party autonomy. This principle enables the parties to choose the law that will be applicable to their contract in the first place, but this rule, however, is not absolute. We find the limitation already in the object of the choice of law itself, when only national law can be chosen as the law applicable to the contract, and not non-state law or some source of international law. For cases in which all other elements relevant to the situation at the time of the choice are located in a country other than the country whose law has been chosen, the choice of the parties shall not prejudice the application of provisions of the law of that other country which cannot be derogated from by agreement. A similar rule applies at the level of the European Union when it comes to choosing the law of a third country. The contracts specifically mentioned in the regulation, consumer contracts, individual employment contracts, contracts of carriage and insurance contracts also bring with them some restrictions, in which, among other things, the weaker contracting party is protected. And finally, when we talk about the restrictions of party autonomy, we must not forget the restrictions that apply to all types of connecting factors, and not only to the party autonomy as a connecting factor, which are the restrictions that determine the provisions in which rules on public policy and rules of overriding mandatory rules are applicable, which protect the interests of states that must apply foreign law.