Payout evidence belongs with the voucher
A scheduled n8n workflow matches payout PDFs to Lexware card vouchers, handles ambiguity explicitly, and records every attachment result.
The gap after posting
A posted card voucher is easier to review when its original SumUp payout report sits beside it. Without that attachment, a later accountant has to search another system and reconstruct the link manually.
The scheduled workflow
Every morning, the workflow reads the attachment work set, builds one item per expected voucher, and checks the live Lexware voucher before it changes anything. Already-attached evidence is recorded and skipped.
A matching rule identifies the correct Google Drive payout PDF. No match and ambiguous match are separate outcomes. Neither case should silently attach the wrong document.
Controlled write
A dry-run route can record a successful match without an upload. A real run paces Lexware requests, downloads the PDF, uploads it to the expected voucher, verifies that the API returned a file identifier, and records either ATTACHED or ATTACH_FAILED.
Reusable lesson
Document automation is an evidence problem. Make matching rules explicit, preserve ambiguity as a review state, separate dry runs from real writes, rate-limit external APIs, and record the outcome for every work item.
