Short answer: service dogs yes, pet dogs usually only outside, and it depends on that location.
Under the Americans with Disabilities Act, a trained service dog may go inside any business open to the public, In-N-Out included. Staff can ask only whether the dog is required because of a disability and what task it performs. They can't require a vest or ID.
Pet dogs are a separate question. In-N-Out sets its own pet policy, and the ADA doesn't require it to admit pets. Many In-N-Out locations allow dogs on an outdoor patio only. Across the US, health rules generally keep pet dogs out of indoor dining areas, and a patio with its own outside entrance is the usual exception. I couldn't find a published policy for the Vancouver, WA store, and I don't know Washington's local rules for it, so I can't say for certain.
To check, call the Vancouver store or ask a manager when you arrive. Clark County Public Health handles food-service rules for the area if you want the official answer.
🕒 As of October 2026
