Vergi Kimlik Numarası (Turkish Tax Identification Number)

Detects the Turkish tax identification number (Vergi Kimlik Numarası, VKN) issued by the Turkish Revenue Administration (Gelir İdaresi Başkanlığı, GİB). The VKN is a 10-digit number structured as a 3-digit alpha group code (001-999), a 6-digit sequence number and a single check digit. Since 1 July 2006 Turkish citizens use their 11-digit T.C. Kimlik Numarası as their tax number (covered by the separate tr-national-id pattern); the 10-digit VKN remains the tax identifier for legal entities, ordinary partnerships, foreign legal entities and foreign nationals without a Foreign Identity Number.

Type: regex
Engine: boost_regex
Confidence: medium
Confidence justification: Medium confidence: 10-digit numeric strings are common (phone numbers, order numbers, other countries' identifiers such as Saudi national IDs), and the VKN check digit cannot be expressed in a regex, so corroborating tax keywords are required on every tier. The evidence-gated 75 tier is the recommended workhorse per identifier convention.
Jurisdictions: tr
Regulations: KVKK (Law No. 6698 on Protection of Personal Data) (Turkey), Law No. 4358 on Expanding the Use of Tax Identification Numbers (Türkiye), Tax Procedure Law No. 213 (Türkiye)
Frameworks: ISO 27001, ISO 27701
Data categories: pii, government-id, financial
Scope: wide
Risk rating: 7
Platform compatibility: Purview: Compatible, GCP DLP: Compatible, Macie: Compatible, Zscaler: Compatible, Palo Alto: Compatible, Netskope: Unsupported

Pattern

\b(?:00[1-9]|0[1-9][0-9]|[1-9][0-9]{2})[0-9]{7}\b

Corroborative evidence keywords

vergi kimlik, vergi numarası, VKN, tax identification number, tax ID, ID number, identification, ID card, license, permit, registration, certificate, data record, database record, record set, data extract, data export, database table, spreadsheet, data registry (+15 more)

Proximity: 300 characters

Should match

1234567890 — Standard 10-digit VKN
Vergi Kimlik No: 0010005284 — Turkish label with a VKN whose alpha group code is 001
1230005284 — Structure example from the OECD TIN portal (alpha group 123, sequence 000528, check digit 4)
VKN 9990001234 kayıtlıdır — VKN abbreviation label with highest alpha group code 999

Should not match

0001234567 — Leading alpha group code 000 is never issued
123456789 — Only nine digits — too short
12345678901 — Eleven digits — a T.C. Kimlik Numarası shape, covered by tr-national-id instead
IBAN TR330006100519786457841326 — Ten-digit sequence inside a longer digit run — boundary guard prevents partial match
1111111111 — Repeated-digit placeholder — suppressed by AllDigitsSameFilter

Known false positives

Ten-digit numeric sequences in unrelated contexts: Turkish mobile numbers written without the leading zero, order and invoice numbers, and other countries' 10-digit identifiers (e.g. Saudi national ID numbers). Mitigation: Every tier requires corroborating tax keywords or label context within the proximity window; there is no bare value-only tier.
The VKN check digit (10th digit computed over the first nine) cannot be expressed in a regex, so structurally invalid 10-digit numbers can still match. Mitigation: Rely on structure (alpha group 001-999, exact length, word boundaries), AllDigitsSameFilter and keyword evidence.
Sample tax numbers in accounting templates, e-invoice documentation and test data. Mitigation: The high and medium tiers apply the template-exclusion NOT-group to suppress sample content.