Section 845-RICR-00-00-4.7 - BILLINGA. The Corporation shall bill the municipality monthly for the disposal of MSW at the central landfill and the municipality agrees to pay all sums due within thirty (30) days of invoice date.B. The Corporation shall allow an early payment discount. Upon receipt of full payment of an invoice within 20 days of the invoice date which brings the municipality's outstanding balance to zero, the municipality shall receive a one-and-one-half percent (1.5%) discount from the invoice's amount. The municipality's eligibility expires monthly and is renewed monthly with the issuance of each month's invoice, as stated in § 4.7(A) of this Part.845 R.I. Code R. 845-RICR-00-00-4.7