Why check a VAT number at all?
The VAT number on an invoice is not a formality: it is what ties the invoice to a real business registered for VAT. Accept an invoice carrying an unregistered number and you are deducting input VAT with nothing behind it — and at audit that is your responsibility, not the supplier's.
Three moments where this is worth a minute: before accepting an invoice from a new supplier, before opening an account for a customer who wants a tax invoice in their business's name, and when reconciling the details of a long-standing supplier that has changed its trading name.
The VAT number and the numbers it gets confused with
- VAT number — 15 digits, starting with 3 and ending with 3. This is what a tax invoice requires, and what this tool checks.
- The unified number of the business — 10 digits starting with 7. A unified government identifier, not a VAT number.
- CR number — 10 digits issued by the Ministry of Commerce; it is not a substitute for the VAT number on an invoice.
The tenth and eleventh digits of a VAT number carry meaning: if the eleventh digit is 1, the business is a member of a tax group, and the unified number must then appear on the invoice alongside the VAT number.
Where does the result come from?
From the public lookup service of the Zakat, Tax and Customs Authority. The Authority publishes no API for it, so the tool reads the official page on your behalf and shows what comes back: the business name as registered, and its registration status. That is why the check takes a few seconds, and why there is a limit on the number of lookups — too many requests harm the service for everyone.
What comes after the check?
If you are the one issuing the invoices, a correct VAT number is only half the job. The other half is having the invoice digitally signed and reported to the Fatoora platform, as Phase 2 requires. ZATCA Tools handles that half in full — with no certificates and no XML files.