How do you integrate the e-invoice with the inventory management system?

The technical process

1. Order in the inventory management system
2. Delivery and invoicing as before
3. Interface generates the e-invoice in the selected format
4. Validation against the standard
5. Sending via email or over a network
6. Archiving of the structured original

Where it gets tricky

Master data. The standard requires information that is often missing or messy in mature systems:

• Complete addresses with country code
• VAT identification numbers
• Unique tax categories per item
• Units in a standardized key
• Route ID for public contracting authorities

The first validation reveals all of this at once. This is unpleasant, but useful.

Free text line items. "Various as agreed" cannot be cleanly mapped. Those who work extensively with free text need a service catalog first.

What can be avoided

Replacing the inventory management system solely to generate e-invoices. In most cases, a pre-connected interface that generates the format from existing data suffices.

Sequence

First clean up master data, then build the interface. Doing it the other way around builds an interface that reliably generates faulty invoices.