A sublease is an agreement where someone takes over part or all of an existing lease. This type of lease involves at least three parties.Show prospective clients you're ahead of the curve. Download our free Texas sublease agreement template to help you win more clients. Looking to sublease your rental? Easily create a free Sublease Agreement. Sublet a room or add a roommate. It's never been easier to create a sublease agreement. All you need to do is answer a few easy questions and Form Pros' online tool will do the rest. 1. Identify and enter the names of the sublessor and subtenant.