When combining different prices on a subscription, which parameter must remain the same?

When combining different prices on a subscription, the billing interval must remain the same. This is crucial because the billing interval dictates the frequency with which payments are made—be it monthly, annually, or at other specified intervals. If different prices were tied to varying billing intervals, it would complicate the subscription management and lead to confusion regarding when payments should be processed.

Maintaining a consistent billing interval helps streamline the payment process and ensures that both the customer and the service provider have a shared understanding of the timing of charges. This standardization is essential for the seamless operation of billing cycles and for maintaining customer satisfaction.

Other parameters, such as currency type, customer ID, and discount percentage, can vary as they pertain to different aspects of the subscription setup. Currency types may differ based on the customer's location, customer IDs are unique identifiers for different customers, and discount percentages can be applied at the discretion of the business without affecting the fundamental structure of the subscription.