Definition of private international law

Private international law (also known as conflict of laws) is a branch of law that tends to determine which rules apply to an international case, which courts are competent to judge an international dispute and how to resolve conflicts between different legal systems.

A distinction is made between conflict rules and substantive rules.

Conflict rules

Conflict rules, also referred to as choice of law rules, are rules used to determine which rules (State laws, treaties or other rules) should be applied to an international case (for example an international contract) and which courts are competent in international litigations. These rules help determine which legal system governs the rights and obligations of the parties involved and which judge is competent. Conflict rules typically consider factors such as the parties’ citizenship, their place of residence, the place where the contract was executed, the language of the contract, the subject matter of the contract, or the location of a particular event related to the dispute.

Substantive rules

Substantive rules, on the other hand, are the actual rules that apply to a specific case once the appropriate jurisdiction has been determined by the conflict rules. Substantive rules vary across different legal systems and jurisdictions. They govern various areas of private law, such as contract law, tort law, commercial law, property law. These rules differ from one country to another, and private international law aims to address conflicts that arise when different legal systems may apply.

In summary, private international law involves both conflict rules, which determine the jurisdiction whose laws apply, and substantive rules, which are the actual rules (State laws, treaties, private rules, principles or other rules) applied to resolve the legal dispute. Through these components, private international law provides a framework for resolving cross-border legal issues.