It is now possible to add attachments to the invoice regardless of delivery method.
In practice, this means that you who use a pre-system for Fortnox can create an invoice attachments and then send these to the end customer via Fortnox.
In other words, you do not need to log in to Fortnox to send the invoices, but they go directly to the end customer via Fortnox automatically.
Please read more about this in our API documentation: Invoice File Connections