How can I verify a Hungarian company's tax number?
Two separate questions: is the number valid, and is there a company behind it? The first can be settled on paper; the second cannot.
The check digit: catching typos
A Hungarian tax number (adószám) has eleven digits in an 8-1-2 split. The first eight are the core number (törzsszám), whose eighth digit is a check digit: the preceding seven digits are multiplied by the weights 9, 7, 3, 1, 9, 7, 3 and summed, and the check digit is whatever tops the sum up to a multiple of ten.
It follows that only one in ten eight-digit numbers can be a valid core number. If the check digit does not match, the number is certainly wrong — mistyped, or not a tax number at all. This is the one thing that can be decided without any external data.
A valid number is not yet an existing company
The check digit only says the number is formally in order — not that NAV ever issued it. A made-up but mathematically correct tax number passes the check exactly like a real one.
Only a registry answers the question of existence. NAV's public register of VAT-taxable persons tells you whether a taxable person belongs to that tax number, and if so, under what name and registered seat.
The middle digit and the last two
The ninth digit is the VAT code: 1 for those outside the VAT system, 2 for those taxed under the general rules, 3 for taxable persons with special status. This says nothing about the company's reliability — only its way of taxation.
The last two digits are the code of the competent tax directorate. This need not match the county code in the registration number, and for Budapest companies several values occur — 41, 42, 43 and 44 all denote Budapest directorates.
EU VAT number
The EU VAT number used for intra-community trade is the HU prefix plus the core number: a company with tax number 13324223-4-44 has the EU VAT number HU13324223. The middle digit and the last two are not part of it.
The validity of an EU VAT number is checked by the European Commission's VIES system. Having a Hungarian tax number does not imply having an EU VAT number.
Frequently asked questions
How do I know whether a tax number is real?
The check digit shows whether the number is formally correct — our tax number checker verifies it for you. Whether a real company belongs to it is answered by NAV's register of VAT-taxable persons.
What does the middle digit of a tax number mean?
The VAT code: 1 outside the VAT system, 2 taxed under the general rules, 3 special-status taxable person. It describes the mode of taxation, not the company's condition.
Why doesn't the end of the tax number match the company's county?
Because the last two digits name the competent tax directorate, not the county of the seat. In Budapest several directorate codes are in use.
Is checking a tax number free?
Yes. Verifying the check digit and searching NAV's public register of VAT-taxable persons are both free of charge.