1. Receipt and Format Validation
The incoming file is identified: XRechnung (XML), ZUGFeRD (PDF with embedded XML) or conventional PDF? The software validates the format against the EN 16931 specification and checks all mandatory fields. Faulty files are moved to an exception list.
2. XML Parsing and Data Extraction
For compliant e-invoices, structured XML data is automatically extracted: invoice number, date, net/gross amount, VAT, supplier data, IBAN, line items and references. For conventional PDFs without XML, OCR text recognition is used — though it is more error-prone than direct XML processing.
3. Duplicate Detection
The software automatically checks whether an invoice with the same number from the same supplier has already been processed, preventing double bookings.
4. Substantive and Arithmetic Verification
Are the amounts correct? Are tax rates accurate? Does the invoice match a purchase order? Automated systems can cross-reference invoice data with order data and flag discrepancies.
Practical example: A supplier invoices 105 units, but the order was for 100. The software detects the discrepancy and routes the invoice for manual review — instead of automatically authorising payment.
5. Approval Workflow
Invoices that pass automated checks are presented to the responsible employee for approval. Multi-level approval workflows can be configured by invoice amount, cost centre or supplier.
6. ERP and Accounting Handover
The approved invoice is transferred to the target system: ERP, accounting software or DATEV. With structured e-invoices, manual data entry is eliminated entirely — journal entries are generated directly from the XML data.
7. Archiving
The e-invoice is archived in a legally compliant manner. The original format must be preserved: XML for XRechnung, PDF+XML for ZUGFeRD. A simple PDF printout is insufficient. Archiving is tamper-proof with a 10-year retention period.