A unilateral contract is written by a party that sets out all the conditions, but is the only party to have obligations arising from those conditions. While the GTA is and will remain a voluntary agreement, membership helps the parties, both in the insurance sector and in the credit leasing sector, to reduce the administrative burden for cases of replacement vehicles, allowing for smoother and more transparent cooperation and improved results across the line. The simplest way to understand unilateral commercial contracts is to analyze the word “unilateral”. In the simplest sense of the term, unilateral contracts involve an act performed by a person or group alone. In contract law, unilateral contracts allow a single person to make a promise or agreement. .