The main use cases for bill update is for marking bills as processed or marking bills as failed but you can also use this endpoint to PATCH general information on the bill. Note that if you make any updates to a bill that has already been sent to the PMS, it will not be resent. In such cases, you will need to update or reprocess the bill in the PMS separately to ensure that the changes are reflected.
To mark a bill as failed, you should at minimum provide billing_error, which is the human-readable error that will be visible for the user to see. If you wish to provide some more details on the error without showing it to the user (e.g. a traceback of the error to help debug), you can fill out billing_raw_error.
To mark a bill as processed, provide a minimum of both the ref_number and the billing_date fields. Bills updated with these fields will be considered "Billed".
Bills cannot be marked as both failed and processed in the same request. For example, do not submit ref_number, billing_date and billing_error in the same request object.