Tenants in Washington must obtain explicit written consent from their landlord before subleasing a rental property. A Washington sublease agreement is a contract used when a tenant wants to rent part or all of their residence to another person.Here is a sample sublease agreement you can fill out or use as a template. Create your Washington sublease agreement and sublet your rental. Rent your unit to a subtenant with our attorney-approved template. Residential Rental Forms. Lease: A lease requires the tenant to stay for a specific amount of time and restricts the landlord's ability to change the terms of the rental agreement. The landlord must provide a copy of the rental agreement to each tenant that signs it. The tenant may request one free replacement copy during the tenancy. This agreement is to sublet real property according to the terms specified below.