Read the e-invoice check and ask a supplier for a corrected invoice

Owners, admins, accountants and bookkeepers can ask. It concerns a received invoice uploaded as XRechnung or ZUGFeRD whose check found errors. No switch is needed, and nothing is ever sent without your click.
Open the document. The section E-invoice check gives a verdict ("The e-invoice passes validation.", "The e-invoice has errors. You can still book it; ask the supplier for a corrected invoice.", "Checked with the built-in core rules only ...", "The e-invoice could not be checked." or "This e-invoice format is not checked."), who checked it, and the lists Errors and Warnings with rule code and text. Errors do not block booking. A ZUGFeRD file with the profile MINIMUM or BASIC WL is not an e-invoice under § 14 UStG because it lacks the invoice content.
With errors, the button Request correction opens Request a corrected invoice. Choose Email language: German (preselected) or English; Chinese is not offered. The text is fixed; you cannot change subject or rules.
Recipient offers only addresses the app already holds: the supplier's contact (Contact) and, only if the contact has no address or one on the same domain, the seller contact inside the e-invoice (from the e-invoice), with the warning to check it. With no address you read "No email address is stored for this supplier. Add it on the contact, then open this request again."
Check the Subject and the Email preview. The mail names each broken rule in a fixed sentence, asks for a corrected XRechnung or ZUGFeRD and for the faulty one to be cancelled. Under Note to the supplier (optional) you may add plain text, at most 2000 characters. Replies go to the client's invoice contact email.
Choose Send email, then Yes, send under "Send to the supplier now? This cannot be undone." The request is recorded in the audit log.
Limits: one request per document per 24 hours, 20 per client per day, and none for a voided document. "The email could not be delivered. Nothing was sent; please try again." means nothing went out. "Your role may not contact suppliers." means you lack the right. When the corrected invoice arrives, upload it as a new document.