Square Invoices enable you to request or automatically collect payments from customers for orders created using the Orders API.
The Invoices API makes it easy for you to manage invoices. After you create and publish an invoice using the API, Square follows up with the customer by sending the invoice to the customer's email address or automatically charging the customer's card on file. Square makes it easy for your customers to pay by hosting each invoice on a web page where customers can pay for it.
For more information, see Manage Invoices Using the Invoices API.