The Provision element is used in Salesforce Billing and Subscription Management to support mid-cycle changes and proration logic, which is exactly what is required in this scenario. When a customer changes their subscription partway through a billing cycle, Salesforce can use Provision elements to:

Prorate credits for the unused portion of the original service

Calculate the partial charge for the new service based on the remaining billing period

Accurately reflect the change in the invoice and subscription record

This functionality is part of Amendments and Mid-Term Changes in Subscription Management and supports use cases like upgrades, downgrades, and plan switches.

Option A (Derived Price) calculates pricing based on formulas or derived fields but doesn’t handle time-based adjustments.

Option B (Aggregate Price) is used when rolling up prices from multiple child components or bundles, not for mid-cycle adjustments.

Exact Extracts from Salesforce Revenue Cloud Documents:

Subscription Management Implementation Guide – “Prorated Billing and Provisioning”:“Use Provision pricing elements to handle partial-period charges and credits during plan changes or mid-term amendments.”

Billing Implementation Guide – “Handling Amendments with Pro-ration”:“Provision elements automate adjustments to billing based on service activation or termination dates within the billing period.”