A simple addendum explaining what the Landlord pays and what the Tenant pays will suffice. Plain language is fine as long as it is clear to both parties.The landlord and tenant will agree on who will pay for each utility service. The utility responsibilities should be specified in the lease agreement. Just look at the monthly average and roll the cost into the rent. You must pay the utility bill if the lease makes you responsible. If the utilities are in the landlord's name, but included in the monthly rent, no disclosure is required. "Agreement" includes leases, oral agreements, and any other understandings or contracts reached between a landlord and a tenant. We outline everything to know about including rent with utilities, when it makes sense to have tenants pay the fees, and what to include in a lease agreement. An Illinois lease agreement is a contract that defines the relationship between a property owner and their tenant.