Your end customer subscribes to an annual service from January 1, 2021 to December 31, 2021, and an invoice named INV-001 is generated. Later, your customer cancels the subscription on July 1, 2021, so you have to provide corresponding credit for your customer.

The key information of invoice INV-001 is as follows:

If your customer cancels the subscription on July 1, 2021, so you use the billing engine to generate a credit memo named CM-001 to provide corresponding credit for your customer. The source type of this credit memo is API or BillRun and its source ID is null . The key information of credit memo CM-001 is as follows.

Due to a service dispute, you want to create a standalone credit memo named CM-002 from invoice INV-001. The source type of this credit memo is Invoice, and its source ID is the ID of invoice INV-001. The key information of credit memo CM-003 is as follows.

Later, you want to create a standalone credit memo from the corresponding product rate plan charge for providing ad-hoc credit for your customer. The source type of this credit memo isAdhocFromPrpc, and its source ID is the ID of the product rate plan charge. The key information of credit memo CM-003 is as follows.