The UCR (Unified Carrier Registration) is a program that replaced the (SSRS) Single State Registration System. The UCR Program requires individuals and companies that operate commercial motor vehicles in interstate or international commerce to register their business with a participating state and pay an annual fee based on the size of their fleet. This includes ALL carriers - private, exempt, or for hire. Brokers, freight forwarders, and leasing companies are also required to register and pay a fee unless they also operate as a motor carrier.