The lease may provide that not only shall the tenant pay the landlord an agreed rental, but also that he shall pay some or all of the expenses and carrying charges of the property. In cases where the tenant pays all expenses and charges, the rent paid to the landlord is said to be a "net rental." That is, the landlord's income from the rent of the property is net to him, the tenant meeting all charges in connection with the property. These charges may include taxes, assessments, water rates, fire and plate glass insurance premiums. Interest on mortgages is not usually included among the charges to be paid by a tenant.

It should be a part of the agreement that the landlord may pay any or all of such charges that the tenant fails to pay and that any charge so paid becomes additional rent payable with the next installment of rent under the lease.