A commercial sublease agreement is a statutory document authorizing a third party to occupy a leased property under the original lease agreement. 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. Subletting your office space or commercial property? Easily customize your own Commercial Sublease Agreement. A commercial sublease agreement template is a fundamental and customizable contract between a lessor and the subtenant. This Sublease Agreement is available for use on UpCounsel. What is a commercial sublease? A commercial sublease is an agreement to lease space from a tenant rather than directly from a property owner. Download free Texas commercial lease agreement template online.