Guides

Practical answers about checking the businesses you trade with: VAT and EORI numbers, the reverse charge, sanctions, supplier fraud and e-invoicing.

• How to check an EU VAT number before you invoiceWhy checking a customer’s VAT number matters for zero-rating and the reverse charge, how to do it properly, and the mistakes that catch people out.
• VIES is down: what it means and what to doWhy VIES fails for one country at a time, what its error messages mean, and how to keep invoicing correctly while it’s down.
• The reverse charge explained: EU and UK B2B salesWhen you invoice without VAT and the customer accounts for it instead: services, goods, the conditions, and what the invoice must say.
• How often should you re-check a customer’s VAT number?VAT numbers stop being valid without anyone telling you. When to check again, and what to do when a number you rely on is no longer valid.
• What proof of a VAT number check should you keep?What the EU rules expect before you zero-rate or reverse-charge, what a good record of a check contains, and why a screenshot isn’t enough.
• EORI numbers explained: EU, GB and XIWho needs an EORI number, what the formats look like, where each kind is checked, and why a valid EORI number often shows no company name.
• Northern Ireland XI numbers: VAT and EORIWhy Northern Ireland businesses have XI numbers, when to use the XI or the GB number, and how each is checked.
• Checking Swiss and Norwegian VAT numbersSwitzerland and Norway aren’t in VIES. What their VAT numbers look like, where to check them, and how invoicing their businesses differs.
• Sanctions screening for small businessesWhich lists matter, who to screen and when, how to handle a potential match, and what to do if a match turns out to be real.
• Fake invoices and changed bank details: how to spot supplier fraudThe warning signs of invoice and payment-redirection fraud, and the checks that catch it before money leaves your account.
• Peppol e-invoicing: what it is and how to check a customerHow the Peppol network works, what a Peppol ID looks like, where e-invoicing is becoming mandatory, and how to see whether a customer can receive one.