What each file is for
The PDF/A-3 hybrid invoice is for human review, printing and archiving; xrechnung.xml is what accounting systems read and book. Both contain identical amounts to the cent.
The XML file is named after the invoice number, for example INV-2026-11-00018.xrechnung.xml; credit notes are structured XML as well, with document type code 381.
If the recipient's accountant only needs structured data, forward the XML; attach the PDF only when a printable copy is required.
Importing into DATEV
DATEV Unternehmen online: upload the PDF/A-3 or XML under "Belege erfassen" and DATEV reads the structured fields; on the firm side, DATEV Rechnungsdatenservice can receive the XML data.
Before importing, make sure the customer (debitor) and accounts exist, otherwise you will see "Konto nicht gefunden" and need to create them first.
DATEV books the XML; do not import both the PDF and the XML for the same invoice, or you will create duplicate vouchers.
Importing into Lexware
Lexware Office / Buchhaltung: choose e-invoice import under "Belege", which accepts xrechnung.xml and ZUGFeRD hybrid PDFs; afterwards verify tax codes (19% / 7%), the supplier/customer account and the payment status.
Lexware Warenwirtschaft: use the e-invoice import to read the XML, then check that line items and tax rates match.
If a field is reported missing, it is usually a mandatory field in the target system (such as a supplier number) rather than a defect in the invoice.
The four most common import errors
Missing BuyerReference / Leitweg-ID: public-sector customers require a Leitweg-ID; add it in the company profile and reissue the invoice.
Tax rate does not match the account: check when 19% and 7% apply and never book tax twice on the net amount.
Duplicate import: import PDF and XML only once — book from the XML and archive the PDF.
Non-compliant archiving: GoBD requires the original XML, unaltered and machine-readable, within the statutory retention period.