Guides
What you need to know to check an EU VAT number and keep the proof. Written for businesses trading in the EU and their accountants.
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Invalid EU VAT number: what should you do?
VIES says “invalid”: a format error, a customer not registered for intra-EU trade, or a deregistered number. What the law says, and what to do before invoicing VAT-free.
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What proof of a VIES check should you keep for a tax audit?
What tax authorities and courts expect as proof of a VIES check, what useful proof contains, and why a screenshot is not enough.
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VIES is down: what about the invoice?
VIES goes down often, Germany especially at night. What an outage changes for the invoice, how to date your attempt, and what akwito does during an outage.
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Germany and Spain: why VIES does not return the company name
For Germany and Spain, VIES returns a valid number with no name or address. Why, and how to get an identity confirmed field by field.
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akwito or VIES alone, akwito or viesapi?
VIES alone, viesapi.eu or akwito: price, consultation number, certificate, retention, behaviour during outages. Comparison as of 14 September 2026.