The Merchant Licence is a temporary item in Blacklight: Retribution that can be purchased from the Mini Mart. It allows its owner to send an unlimited number of items within 3 days. It is only available for a duration of 3 days.
As sending 1 item costs 25 ZEN and the Merchant License costs 250 ZEN, it will pay off when a player sends at least 11 items within the 3 days that the license lasts.