The deferred rebate system is the oldest of the methods used by conferences to encourage loyalty from shippers. It is an agreement whereby the shipper is entitled to a rebate from the freight for shipping all of his goods destined for places served by a conference on the ships of the lines who are members of that conference.The rebate applies to shipments made over a specific period of time and is deferred for a further period of time before it is paid, normally several months after the date of shipment.The level of the rebate can vary from conference to conference but typically it is 10%, calculated on the basic freight rate, that is to say the rate before the application of surcharges and any extras.