There are three different types of rental agreements: 1) Month-to-month rental agreements do not contain specific time limits. The average apartment lease length is one year to 15 months from the time you move in.Residential Rental Forms. The Washington lease agreement is the most common type of lease form and can be used for leasing rental property over a fixed period. This means that if you rent out your property for less than 14 days each year, you don't have to pay taxes on your rental income. Our firm has encountered representing homeowners renting on a short-term basis, here are a few thoughts on how best to prepare your property for this use. The landlord must receive written notice of your move-out date 20 days before the end of the rental period. This allows the tenant to pay rent every month without having to commit to a long-term lease. Strategies When Renting Your Properties Through VRBO or AirBNB. For monthtomonth leases, tenants usually need to provide a 20day written notice before the end of the rental period.