Tortious interference is a legal theory intended to allow parties to contract to fulfill contractual obligations without thirdparty interference. Interference can occur when an outside party purposefully leads someone in a business agreement to break the terms of the agreement.Tortious interference is an intentional and wrongful act that negatively impacts your contractual relationships. You can file a tortious interference lawsuit if a third party disrupts your business contract or hinders your professional relationship. Tortious interference with business relations involves a third party using false claims against a business in order to drive business away. Tortious interference with business relations involves a third party using false claims against a business in order to drive business away. Although it is not always necessary, a written contract can support a tortious interference claim. Proving to a court that a third party intentionally interfered in a business relationship or contract is complicated. Partnership dissolution agreements. Business purchase and sales contracts.