EN 16931 e-Invoice Lint — DE / FR / IT / BE / PL

Free online check: https://getreadystack.com/tools/en16931-einvoice-lint

This extension reads the invoice payload or field mapping you are editing — the JSON, YAML or XML your code fills in before it hands a document to an access point — and checks it against the EN 16931 core invoice model and the national rule set (CIUS) of the country it detects.

What it checks

29 rules, in four groups.

Core EN 16931 business terms. BT-1 invoice number, BT-2 issue date, BT-5 currency, BT-24 specification identifier, BT-23 business process, BT-31 seller VAT identifier, BT-48 buyer VAT identifier, BT-49 buyer electronic address, BG-23 VAT breakdown, BT-112 total with VAT, BT-115 amount due, BT-9 / BT-20 payment due date or terms, BT-30 seller legal registration identifier, BG-25 invoice lines.

National CIUS fields, applied only to the country it detects. Leitweg-ID (BT-10) for XRechnung 3.0 in Germany; SIREN / SIRET (scheme 0009) for France; Codice Destinatario or PEC for FatturaPA in Italy; NIP for KSeF in Poland; enterprise number (Peppol scheme 0208) for Belgium. Spain (Verifactu) is recognised for the date rules.

Things that validate as XML but fail as an invoice. A zero or exempt VAT category with no BT-120 exemption reason and no BT-121 VATEX code. An electronic address with no EAS scheme identifier. A stale XRechnung 1.x / 2.x specification identifier. A UBL 2.0 namespace. Monetary amounts carrying more than two decimals. A CII date declared format 102 but written with dashes.

Dates, against the day you run it. A Factur-X MINIMUM or BASIC WL profile, a PDF or e-mail fallback switch, and any mandate date hardcoded in the file are compared with the real dates for the detected country: France 2026-09-01 issuing (art. 289 bis CGI), Germany 2025-01-01 receipt and 2027-01-01 issuing (§ 14 UStG), Poland 2026-02-01 / 2026-04-01 (KSeF), Belgium 2026-01-01, Italy since 2019 (D.Lgs. 127/2015). The severity changes when the date passes, so a warning in January is an error in September. This is the part generated code gets wrong most often: the model was trained before the dates moved.

Commands

• e-Invoice Lint: Check this file — free, no key. Findings appear inline as diagnostics and as a text report in the output channel.
• e-Invoice Lint: Sweep workspace and write report (licence) — walks every **/*.{json,xml,yaml,yml} in the folder, applies all 29 rules to each, and writes a dated einvoiceLint-report.md you keep, commit and hand to an auditor.
• e-Invoice Lint: Enter licence key

Free and paid

Checking the file in front of you is free and complete: every rule runs, nothing is withheld, no watermark, no counter. The licence covers a different job — the whole workspace in one pass and a dated report file of your own. $29 once, one licence key per person or team seat: https://getreadystack.com/api/buy/cl/polar_cl_KQWFnU1FA20UW0fJUPyv4JcDLH8BLJkK3rf722j26cC

Yardstick

A German tax adviser's time fee is set by StBVV § 13 at EUR 30–70 per half hour, that is EUR 60–140 an hour. One review of one mapping costs more than the licence.

Notes

Everything runs locally. No file, no fragment and no telemetry leaves your machine; the online version runs the same engine in your browser tab. Findings are advisory and are not legal advice.