Office Space Lease-Pay Pro rata Share of Expenses is an agreement between a tenant and a landlord where the tenant pays a pro rata (proportional) share of expenses related to the office space they are renting. This includes expenses such as property taxes, insurance, utilities, maintenance, and repairs. The tenant’s share of these expenses is typically based on the size of the office space they occupy and the length of their lease. There are two types of Office Space Lease-Pay Pro rata Share of Expenses: Gross Expense Lease and Net Expense Lease. With a Gross Expense Lease, the tenant pays a set amount of the expenses, regardless of the actual amount of the expenses. With a Net Expense Lease, the tenant pays a percentage of the actual expenses incurred.