By Skagit Safety Services · Reviewed by Bert Markley, Director of Training (30+ years in private security) · Last checked October 2026. General information, not legal advice — laws change, and your attorney has the final say.
The short version
- If someone isn’t allowed to be there and knows it, it’s trespass — a crime in Washington.
- Post signs, fence what you can, and tell people directly to leave and not come back. Write it down.
- Security asks trespassers to leave and calls the police for anyone who refuses.
What counts as trespass in Washington
Under Washington law, a person “enters or remains unlawfully” when they are not licensed, invited or otherwise privileged to be there (RCW 9A.52.010). Knowingly entering or remaining unlawfully in a building is criminal trespass in the first degree, a gross misdemeanor (RCW 9A.52.070). Knowingly entering or remaining unlawfully on someone else’s premises in other circumstances is criminal trespass in the second degree, a misdemeanor (RCW 9A.52.080).
Permission to be in the public part of a building is not permission to be in the parts that are not open to the public — like a back office, a maintenance room or a resident-only hallway (RCW 9A.52.010).
Why posting and notice matter
The law looks at whether someone had permission, and whether they were told they didn’t. For unfenced, apparently unused land, a person is treated as having permission unless they were told otherwise in person or the property was conspicuously posted (RCW 9A.52.010). For land that is open to the public only at certain times, posting the prohibited hours conspicuously matters too.
Washington also gives a defense when the property was open to the public at the time and the person followed all lawful conditions of access (RCW 9A.52.090). In practice: post clear signs, post your hours, and tell people directly — and write it down.
Practical steps that work
- Post clear “No Trespassing” and “Residents and guests only” signs at entrances, and post hours for amenities and parking.
- Fence and lock what you can — especially construction sites and closed buildings.
- When someone is not allowed, tell them clearly that they must leave and may not return, and note the date, time, who told them and a description.
- Keep an incident report for every contact, so you can show a pattern to the police. Use our free incident report form.
- Call the police non-emergency line for someone who refuses to leave, and 9-1-1 if anyone is in danger.
- Ask your local police department whether it has a trespass authorization or trespass agreement program for property owners.
What a security officer does — and doesn’t do
Our Public Safety Officers patrol, ask trespassers to leave, document every contact, and call the police when someone refuses or it isn’t safe. They are private security, not police — Washington law prohibits security guards from acting in a way that would make someone believe they are a sworn peace officer (RCW 18.170.170). See what security officers can legally do in Washington.
Questions
Is trespassing a crime in Washington?
Yes. Knowingly entering or remaining unlawfully in a building is criminal trespass in the first degree, a gross misdemeanor (RCW 9A.52.070). Knowingly entering or remaining unlawfully on other premises is criminal trespass in the second degree, a misdemeanor (RCW 9A.52.080).
Do I need No Trespassing signs?
Signs help. For unfenced, apparently unused land, Washington treats a person as having permission unless they were told otherwise in person or the land was conspicuously posted (RCW 9A.52.010). For buildings and fenced or used property, clear signs and telling the person directly still make enforcement easier.
Can security remove a trespasser?
Security officers can ask a trespasser to leave and call the police. Use of force is limited by law; our officers de-escalate and call police rather than physically removing people.