Free tools
Invoicing tools
Quick, free tools for the numbers and decisions around an invoice. The calculators run in your browser; Invoice Passport uses only the country and business facts you choose. No signup.
Evidence-led checker
Invoice Passport
See document content, structured-file export, and network delivery as three separate readiness lanes, with the rule version and official sources shown.
VAT calculator
Add VAT to a net amount, or work backwards to remove VAT from a gross amount, at any rate. The breakdown updates as you type.
Late payment interest calculator
Work out the interest on an overdue invoice from the amount, an annual interest rate, and how many days late the payment is.
Invoice due date calculator
Pick a calculation start date and your payment terms to see the resulting due date. The calculator uses that date as day zero.
EN 16931 e-invoice validator
Upload a UBL or CII e-invoice and it is checked against the pinned XML schemas and EN 16931 business rules, plus the Peppol BIS Billing 3.0 or XRechnu...
Need the invoice itself?
Once the numbers are right, create a professional invoice with country-aware fields where supported. No signup, no card.
Open the invoice generator