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.Here, we look at ways to sublease your unused office space to help you mitigate the financial impacts of the Coronavirus shutdown. Simply call (214) 272-2111 and ask to speak to one of our brokers. A commercial sublease agreement also requires written consent from the property owner for the space to be sublet. Dig up your leasing contract and make sure it allows for subtenants. A commercial sublease agreement is a statutory document authorizing a third party to occupy a leased property under the original lease agreement. Please use the form below to ask any question. We will attempt to answer as quickly as possible. A commercial sublease is the act of a tenant re-renting space they currently lease to a subtenant.