What happens if a Washington tenant does not pay the increased rent?
If the increase notice was valid (correct form, correct advance period, effective on or after the notice's effective date), the higher rent is the legal rent on that date. The tenant who pays only the old amount is short-paying and the landlord may serve a pay-or-quit notice (14 days for pay-or-quit under RCW 59.12.030, 10 days for violations) for the deficiency. If the increase notice was defective, the old rent is still the legal rent and the tenant is current. The defectiveness of an increase is a defense to eviction.
Source: RCW 59.18.140 (90-day advance notice for any rent increase, HB 1217)
This is an informational answer based on RCW 59.18.140 (90-day advance notice for any rent increase, HB 1217) as of early 2026. It is not legal advice. Housing law changes year to year and local ordinances (especially in rent-controlled or rent-stabilized cities) can override or add to state law. For contested cases, consult a Washington-licensed attorney.