1. You sell an enterprise resource planning order product in the UK.
2. The billing treatment associates your order product with the finance book you use to track your ERP sales.
3. Your billing rule creates an invoice line for that order product.
4. The treatment creates a lookup to the invoice line in one of the finance book’s finance periods. Salesforce Billing chooses the finance period based on the date of the invoice line’s creation and matching legal entities between the billing treatment and finance period.