HP Tuners uses a credit-based licensing system. Credits are used as currency to purchase licenses for the different modules in a vehicle. Licensing a module gives you the ability to tune it. The number of credits necessary to purchase a license varies depending on the vehicle.
Many vehicles are (2) credits for licensing the ECM/PCM, and may have additional options such as a TCM, FICM, or CCM.
You can find a complete list of supported vehicles and credit cost on our supported vehicle page here.