If you do not provide the correct information on the invoice, you will receive an immediate error notification.  Users of the web-interface will not be able to send their invoices until all validation rules are met.

If you send via another protocol, you will receive instant responses regarding the status of your documents, and why they are failing the validation rules.

Up to date validation rules and their explanation can be found on RWE's Support Homepage - https://rwe.support.tradeshift.com