EU invoice preflight
A plain invoice you can save as a PDF, plus a checklist for fields that are often missing when an invoice gets sent back. You pick the VAT wording. The draft stays in this browser.
Rule notes quote the public text for codes such as BR-IC-01, BR-G-01, BR-DE-15 and BR-AE-10, and say what to change. The field map names which boxes match an EN 16931 term. Not a validator.