Parties generally are free to negotiate terms without any legislative interference or rules. However, commercial leases share a great deal in common with residential leases as the have a common history. They must be for a term certain and grant exclusive right of quiet possession. Identification of parties: description of premises, time period of the lease (i. e. fixed term or revolving. It is substantially more common for commercial leases to be for fixed term periods and to be for lengthier periods than residential leases. Commercial tenants generally want to security of having a longer time period guaranteed for their commercial premises. : rental payment. For commercial leases rental can be a fixed amount per month for more simple leases. More commonly, rent is based on the square footage of the premises but can also be based on sales: alterations permitted by the tenant. Remember that under the common law no tenant may make changes to the land or premises without permission.