The VAT number (VAT ID) in Slovakia is a ten-digit number that always starts with the prefix SK and the digits 10, 20 or 40 (similar as the Czech VAT ID number). Natural persons have the number 10 at the beginning, legal persons (limited liability company or joint stock company) have the number 20 and foreign persons registered for tax purposes in the Slovak Republic have the prefix SK and the number 40 at the beginning.
The VAT number is assigned only by the Slovak Tax Office on the basis of a registration application.
If a person presents the tax number without the prefix "SK", it means that they are not registered for VAT in the Slovak Republic, but only for income tax (personal income tax, corporate income tax).
How do you find out if the Slovak VAT No. is valid?
If you want to check whether someone is registered for VAT in Slovakia or whether the submitted Slovak VAT ID No. is valid, then you basically have the possibility to use the VIES portal of the European Union.