Mr. Encoder

TCKN / VKN Validator - Turkish ID & Tax Number

Check Turkish national identity numbers (TCKN, 11 digits) and tax identification numbers (VKN, 10 digits) with their official checksum algorithms.

How to use

  1. Type or paste a number: 11 digits are checked as a TCKN, 10 digits as a VKN.
  2. See instantly whether it is valid and, if not, which checksum rule failed.
  3. Use Bulk validate for lists, or Generate test numbers to get valid dummy data for your tests.

Frequently asked questions

What are TCKN and VKN?

TCKN (T.C. Kimlik Numarası) is the 11-digit national identity number of Turkish citizens. VKN (Vergi Kimlik Numarası) is the 10-digit tax identification number given to companies and other taxpayers. Both are required fields in Turkish e-invoice (e-Fatura/e-Arşiv) and e-commerce integrations.

Does a valid result mean the number belongs to a real person?

No. This tool only checks the mathematical checksum rules offline; it does not query any government database. A number can pass the checksum and still not be assigned to anyone.

How is the TCKN checksum calculated?

The first digit cannot be 0. The 10th digit is ((d1+d3+d5+d7+d9)×7 − (d2+d4+d6+d8)) mod 10, and the 11th digit is the sum of the first 10 digits mod 10.

Can I use the generated numbers in production?

No. Generated numbers are random test data for development and QA only. They are not tied to real people or companies and must not be used to impersonate anyone or in real transactions.

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