Home VKN (Vergi Kimlik Numarası) Turkey
Turkey VKN (Vergi Kimlik Numarası) validator
How the VKN (Vergi Kimlik Numarası) format works
- Format
- 10 digits with a weighted mod-10 check digit
- Example
- 4540536920
Things to watch for
- The VKN is Turkey's 10-digit company tax number — distinct from the 11-digit TC Kimlik number issued to individuals
- The weighted check-digit formula is unusually fiddly (a per-digit modular transform with a 0-to-9 remap step) — this implementation is verified against a known-valid reference number
- Checksum only — a pass doesn't confirm the VKN is currently registered or active with GİB
^[0-9]{10}$The VKN (Vergi Kimlik Numarası, tax identification number) is the 10-digit number Turkey’s Revenue Administration (Gelir İdaresi Başkanlığı, GİB) assigns to businesses and other entities that need to file taxes — companies, partnerships, and organizations — for example 4540536920. It appears on invoices, tax filings, and official correspondence with GİB, and it’s the number a business quotes when registering for VAT or corporate tax in Turkey.
Not the same number as TC Kimlik
It’s easy to confuse the VKN with Turkey’s TC Kimlik number, but they’re different identifiers for different purposes. TC Kimlik is an 11-digit number issued to individuals as a national identity number; the VKN is a separate 10-digit number for businesses and other taxable entities. An individual acting as a sole trader may end up associated with both — an 11-digit TC Kimlik as a person and a distinct 10-digit VKN as a taxpayer — but the two numbers, digit counts, and checksum formulas are unrelated. If you’re looking for the personal identity number, use our separate TC Kimlik validator.
Why the tenth digit exists
The VKN’s check digit comes from an unusually intricate calculation: each of the first 9 digits goes through its own per-digit modular transform (a positional addition, then a position-dependent multiplication, with a remap of any zero result) before the results are summed and reduced to a final digit. It’s fiddlier than a typical Luhn or mod-11 check, but the effect is the same — a single mistyped digit is caught because it almost never survives the transform intact.
What this check doesn’t tell you
A pass confirms the 10 digits are internally consistent — not that the VKN is currently registered or active with GİB.
Scope: this page and tool cover VKN format and checksum validation only — not GİB registration status.
Content last reviewed 2026-08-09.
VKN (Vergi Kimlik Numarası) FAQ
What's the difference between a VKN and a TC Kimlik number?
They're different identifiers issued by different systems: TC Kimlik is Turkey's 11-digit national identity number for individuals, while the VKN is a separate 10-digit tax number for businesses and other taxable entities, with its own distinct checksum formula.
Who needs a VKN?
Companies, partnerships, and other entities that register with Turkey's Revenue Administration (GİB) for tax purposes — including VAT and corporate tax — are assigned a VKN, which then appears on their invoices and tax filings.
Does a valid VKN checksum mean the number is currently active with GİB?
No. This tool only confirms the 10 digits pass GİB's weighted check-digit formula — it doesn't query GİB's systems, so it can't confirm the VKN is currently registered or in active use.