FW-DUE warning FakturWire check
FW-DUE — due date is before the issue date
What it means
The payment due date falls before the invoice issue date — which would mean the invoice was due before it existed. Almost always a swapped or mistyped date.
What triggers it
dueDate is earlier than issueDate.
How to fix it
Set a due date on or after the issue date:
{ "issueDate": "2026-07-01", "dueDate": "2026-07-31" } Dates are ISO YYYY-MM-DD. If you use payment terms in days, add them to the issue date.
Check your invoice now. Paste it into the free validator — it flags FW-DUE and every other EN 16931, Peppol and XRechnung rule, each with the fix.
Or run the same check via API:
curl -X POST https://fakturwire.com/v1/validate \
-H "authorization: Bearer $FW_KEY" \
-d '{"invoice": { ... }, "profile": "en16931"}'