It is now possible to generate invoice in bulk with the newly released Invoices import module. You will find this module in the Integration center along with the other import modules. The workflow is as follows: you provide required details in a CSV (at the very minimum the order id, the invoice number to generate and the SKU to invoices) and import it with the module; the system will then gather all necessary details (such as customer billing and delivery addresses) in order to create the invoices.
The invoices to generate must be linked to an order and this order, which is why the CSV must provide an order id. It is possible to only invoice some SKUs of the order and/or some quantities of the SKU, which lets you link multiple invoices to a specific order. Validations will be done to check that SKUs have not yet been invoiced for the order.
It is also possible to provide unit prices or let the system gather them from the related order.
Importing a CSV file to generate invoices in bulk