How is the Hungarian VAT check digit calculated?

Take the first seven digits of the 8-digit ANUM, multiply them by weights 9, 7, 3, 1, 9, 7, 3, and sum the products. The check digit is (10 minus (sum modulo 10)) modulo 10, and it must equal the eighth digit.

The ANUM is the core 8-digit VAT identification number. The full Hungarian VAT number is HU plus this ANUM. A longer domestic 11-digit tax number embeds the same 8-digit ANUM as its first eight digits.

How many digits does a Hungarian VAT number have?

The EU-format Hungarian VAT number is HU followed by exactly 8 digits. The tool accepts the number with or without the HU prefix and ignores spaces and dashes.

Does a valid check digit mean the company is VAT-registered?

No. A valid check digit confirms the number is internally consistent, not that the business is currently registered for VAT. Use the EU VIES service to confirm active registration.

Is my VAT number sent anywhere?

No. The check digit is computed entirely in your browser, so the VAT number never leaves your device.

Hungary VAT Number Validator

A Hungarian VAT number (ÁFA szám) in EU format is the prefix HU followed by an 8-digit ANUM. The ANUM carries a trailing check digit that lets you confirm a number is internally well-formed before relying on it for e-invoicing or NAV online reporting. This free validator runs that exact check in your browser.

How it works

The 8-digit ANUM uses a weighted check digit:

Strip the optional HU prefix and any spaces, leaving 8 digits.
Multiply the first 7 digits by the weights: 9, 7, 3, 1, 9, 7, 3.
Add the 7 products together.
Compute the check digit as (10 - (sum mod 10)) mod 10.
The number is valid when that equals the 8th digit.

The tool shows the weighted sum and the computed check digit so you can see precisely why a number passed or failed.

Example

Validate HU12345676 → ANUM digits 1 2 3 4 5 6 7 6. The weighted sum of the first seven is (1×9)+(2×7)+(3×3)+(4×1)+(5×9)+(6×7)+(7×3) = 144. 144 mod 10 = 4, and (10 − 4) mod 10 = 6, which matches the eighth digit, so the number is valid.

Notes

A valid check digit confirms the VAT number is well-formed, not that the business is registered. To confirm an active registration, use the EU VIES service or the Hungarian NAV registry. Everything runs locally — your VAT number never leaves your device.