Turkish test data generator (TCKN, IBAN, VKN)

What is it for?

Try forms, APIs and databases with Turkey-specific fields without real people’s data: test TC kimlik no and IBAN validation, fill a demo database, prepare CSV or JSON imports.

Tick the fields, enter a count from 1 to 1,000, add a seed for reproducible output and press “Generate test data”. The validator tab checks pasted TCKN, VKN and IBAN values line by line.

How are the TCKN check digits calculated?

A TCKN has 11 digits and the first cannot be 0. Digit 10 is the sum of the odd-position digits (1, 3, 5, 7, 9) times 7, minus the sum of the even-position digits (2, 4, 6, 8); digit 11 is the sum of the first ten digits. Both are taken modulo 10, and because the first value can be negative, JavaScript needs ((x % 10) + 10) % 10.

d10 = ((d1+d3+d5+d7+d9) × 7 − (d2+d4+d6+d8)) mod 10
d11 = (d1+d2+…+d10) mod 10

Example 10000000146: odd positions give 1+0+0+0+1 = 2, and 2 × 7 = 14; even positions sum to 0; 14 mod 10 = 4, so digit 10 is 4. The first ten digits sum to 6, so digit 11 is 6. It matches the -(3 × odd sum + even sum) mod 10 form in python-stdnum.

The VKN algorithm

A VKN has 10 digits. The tool uses the commonly used algorithm; an official GİB algorithm could not be verified. Number the first nine digits i = 1…9 from the right. For each digit d, c1 = (d + i) mod 10. If c1 is 0 the contribution is 0; otherwise c2 = (c1 × 2^i) mod 9, with 0 becoming 9. The check digit is (10 − sum of c2) mod 10.

Example: 454053692 gives c2 values 6, 4, 9, 4, 0, 6, 2, 3, 6 from right to left; the sum is 40 and the check digit 0, so 4540536920 is valid and 4540536921 is not. Source: python-stdnum vkn module.

TR IBAN structure and MOD 97

A TR IBAN has 26 characters: TR, 2 check digits, a 5-digit payment service provider code (commonly called the bank code), a reserve digit 0 and a 16-character account number, left-padded with zeros. The structure follows article 4 and annexes 2–3 of the Central Bank’s Tebliğ 2008/6, consolidated through 2021: Tebliğ text.

TR kk bbbbb 0 aaaaaaaaaaaaaaaa
kk = 98 − (n mod 97)   n: BBAN + "TR00", first 4 characters moved to the end, A=10 … Z=35

The check digits use ISO 7064 MOD 97-10: join TR00 and the BBAN, move the first four characters to the end, turn letters into numbers (A=10 … Z=35; T=29, R=27) and write 98 − (n mod 97) with two digits. A valid rearranged IBAN leaves remainder 1 modulo 97. Example: bank code 00001 and account 0000000000000001 give TR610000100000000000000001. The Tebliğ allows letters A–Z in the account area; the validator accepts them, the generator makes digits only.

With an empty bank code each row gets a random one. Real bank codes were not verified, so there is no code list; a random code, even 99999, is not guaranteed to be fictional, assigned or unassigned.

Why are phone and address format-only?

A mobile number looks like +90 5XX XXX XX XX; the tool makes a 5 plus 9 random digits. No officially reserved fictional range could be verified, so this is only a format. It is a format-valid sample and may belong to a real subscriber. Do not call these numbers or send SMS to them; use them only in test environments that send no SMS.

Addresses combine the tool’s own small lists: invented streets such as “Test Sokak” or “Deneme Caddesi”, a random building number, a real province name and a format-only 5-digit postcode. These synthetic combinations may coincide with real addresses; never use them for deliveries. The output labels them fictional addresses. Names are invented combinations.

Responsible use

• Never use the data for identity, payment or official forms.
• Random values can coincide with real records.
• Real personal data must be handled appropriately under Law No. 6698 (KVKK); prefer test data over real customer data in staging and demos.
• Keep the markers: the table caption, the # TEST DATA CSV line and the _test_data JSON flag.

The tool makes no NVİ, MERNİS or GİB query, looks up no real person or account and sends no network request.

Limits

• The validator is mathematical only: it does not check whether a number belongs to a real person, company or account.
• Generator and validator handle at most 1,000 rows each.
• A seed has up to 32 ASCII letters, digits, _ or -. The same seed and settings give the same output; switching a field off leaves other columns unchanged. A new version may change the output.
• In CSV, cells starting with +, =, - or @ get a leading ' so spreadsheets do not run them as formulas; the phone column shows '+90 …. The first line is a # note; skip it when importing.

Algorithms and vectors were rechecked against their sources on 11 October 2026.