A Washington sublease agreement is a contract used when a tenant wants to rent part or all of their residence to another person. Tenants in Washington must obtain explicit written consent from their landlord before subleasing a rental property.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. Please fill out this form and we will get in touch with you shortly. Here is a sample sublease agreement you can fill out or use as a template. A sublease is a rental agreement (fixed-term or month-to-month) between tenants. Edit, sign, and share Landlord Tenant Sublease Package - Washington online.