Systems, methods, and computer program products use combinations of international mobile equipment identity (IMEI), international mobile subscriber identity (IMSI), and account information to determine if a customer is eligible for service credit in near real-time. The customer needs an active account prior to inserting a subscriber identity module (SIM) into a device and powering on the device for the system to determine credit eligibility. No further customer action is required. The credit application process determines credit eligibility based upon device credit eligibility, account tenure, and/or credit rules, and applies the credit to the customer's account. The customer may be proactively notified when the credit is applied. The credit and tenure rules may be changed as the industry and business needs change to remain competitive in the industry. The SIM used is configured with software to lock the SIM to the device upon first power-on.