In a sublease arrangement, tenants must continue to fulfill their rent obligations to the original landlord as outlined in the lease agreement. A California sublease agreement is a written arrangement that involves a residential tenant leasing their rental property to a subtenant.A California sublease agreement is a document between a current tenant (sublessor) and a subtenant for residential use. A sublet, or sublease agreement, adds someone new to an existing lease. A sublease agreement is a legal document allowing existing tenants to rent out their rented space to another party, the subtenant. Create your California sublease agreement here. Rent your unit to a subtenant and download our free template. California law requires tenants to seek explicit, written permission from their landlords to sublet if it is not already allowed in the lease. You fill out the rental application. For example, bad tenants.