A monthly minimum fee is a charge in some merchant services agreements that guarantees the provider a minimum amount of processing revenue each month. If the fees generated by the merchant's card transactions, such as the merchant discount rate or markup above interchange, are below the agreed minimum, the provider charges the difference. For example, with a minimum of 25 units of currency, a merchant whose transactions generated 15 units of fees in a month would pay an extra 10. A merchant that exceeds the minimum pays nothing extra. The fee is designed to cover the fixed costs of servicing an account and is most often charged by traditional acquirers and independent sales organisations. Many payment facilitators and online providers have dropped it in favour of simple pay-as-you-go pricing. Merchants comparing offers should count it alongside a gateway monthly fee, PCI fee and other fixed charges.