How does a Washington landlord calculate a legal rent increase?
Step 1: confirm the unit is covered (most are, but Buildings with certificate of occupancy issued within the last 12 years (rolling exemption) may be exempt). Step 2: calculate the cap: lower of 7% + CPI or 10% flat. Step 3: multiply current rent by the cap to get the maximum dollar increase. Step 4: serve the proper advance notice (RCW 59.18.140 (90-day advance notice for any rent increase, HB 1217)). Step 5: the new rent takes effect on the notice's effective date, no earlier.
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.