National Process Server Network (NPSN) NPSN is a trusted nationwide directory connecting law firms, businesses, and individuals with verified process servers, court-runners, and private investigators. We simplify finding reliable professionals for service of process and related needs— including skip-tracing, record retrieval, e-filing, courier services, and investigations. As the “#1 National Process Directory,” we ensure members meet high standards of professionalism, helping legal clients get dependable support while giving process servers a platform to grow their reach.