The invoice is usually set on a recurring basis so the customer knows how much they owe each month based on their parking habits. The breakdown of parking fees may differ from garage to garage (i.e., hourly, daily, weekly, monthly parking rates) and a monthly parking invoice lets the customer know what exactly they are being charged for. All charges, including any unpaid balances from previous invoices, will be added up for a monthly grand total. The customer must pay this amount before or on the date written at the bottom of the invoice.