A Washington sublease agreement is a contract used when a tenant wants to rent part or all of their residence to another person. Create your Washington sublease agreement and sublet your rental.Rent your unit to a subtenant with our attorney-approved template. This Washington Sublease Agreement. ("Agreement") is entered into on. The Sublessor and Sublessee are together referred to as the "Parties. " The Parties agree that the Sublessor shall sublet and the Sublessee shall take possession. Here is a sample sublease agreement you can fill out or use as a template. Imagine getting a call from the tenant in your rental property one day, and the tenant wants to sublease his home in Seattle, WA. Residential Rental Forms.