Private investigator services in Washington are governed by the RCW 18.165 (Private Investigators) and regulated by the Washington State Department of Licensing — Business and Professions Division. A state-level license is required to operate as a private investigator for compensation in Washington.
Quick Facts: Washington PI Licensing
| License required | Yes |
| Licensing authority | Washington State Department of Licensing — Business and Professions Division |
| Governing statute | RCW 18.165 (Private Investigators) |
| Official license lookup | https://professions.dol.wa.gov/s/license-lookup |
| Authority website | https://www.dol.wa.gov/business/privateinvestigators/ |
| Last reviewed | 2026-05-17 |
Verifying a PI's License in Washington
Before retaining any private investigator in Washington, verify the individual’s license is active and in good standing. The Washington State Department of Licensing — Business and Professions Division maintains a public license search at https://professions.dol.wa.gov/s/license-lookup. Search by the individual’s name or company name; the record will show the license number, status, and any disciplinary history on file.
What This Means for Hiring
Washington’s licensing requirement means the investigator you hire has, at minimum, completed the state’s training and background screening process. It does not guarantee competence on your specific case — surveillance, family-court, corporate, and skip-trace work each demand specialized experience. When evaluating a Washington PI, ask about case-type specialization, evidentiary chain-of-custody process, and prior testimony in the jurisdiction where your matter is pending.
Reference: All 50 States + DC
For licensing requirements in other jurisdictions, see the full PI licensing reference map.