When a new car is first put on the road, it has to be registered with the Registrar of Motor Vehicles at the Road Transport Department, which is managed by the Kenya Revenue Authority. 

This task is typically performed by the vending agent in order to expedite the process, but it can be performed by the purchaser if he or she so desires. If you buy a used car, the previous owner is responsible for tearing the bottom portion of the registration certificate, filling it out, and sending it off, while you are responsible for completing the reverse of the remainder and sending it off.