TCKN (T.C. Kimlik Numarası)

TCKN, T.C. Kimlik Numarası, the Turkish Republic Identity Number, is the 11-digit number assigned to every Turkish citizen, once, for life, at birth or at naturalization. It appears on the Turkish national ID card, is printed or embedded on nearly every official document a Turkish citizen holds, and functions as the anchor identifier almost every Turkish regulatory or KYC system checks against: BTK's SIM-registration rule, MASAK's remote customer-identification rule, KBS's hotel-guest notification, and e-Devlet login itself all key off the TCKN. Foreign residents receive the same kind of identifier under a distinct prefix, a Yabancı Kimlik Numarası (YKN), beginning with the digits 99, issued by the same population-registry system.

Where it comes from

The TCKN was rolled out as part of MERNİS, Türkiye's Central Population Administration System, a Ministry of Interior modernization project, administered through NVİ (the General Directorate of Population and Citizenship Affairs), that digitized what had previously been a paper-based population registry. Law No. 5490, the Population Services Law, is the statutory basis for how the registry, and the TCKN within it, is maintained today. Authoritative, real-time verification of a TCKN against a person's declared name and birthdate runs through KPS, the Kimlik Paylaşım Sistemi (Identity Sharing System), the web service authorized institutions (banks, telecom operators, government agencies) query to confirm a match, rather than trusting whatever a person types into a form.

Why it's worth contrasting with a DID

A TCKN and a Decentralized Identifier (see DID) solve an adjacent problem in opposite ways. Both are unique, durable identifiers a person carries across many interactions. But a TCKN is issued, controlled, and revocable by a state population registry: you don't generate one yourself, and no cryptographic key you hold makes it yours the way a DID's underlying keypair does. A DID is self-generated and self-controlled by design; a TCKN is authority-issued and authority-controlled by design. Neither is a substandard version of the other (they answer different questions ("who does the state say this is" versus "what identifier does this person control the keys to") and a real-world Turkish KYC flow typically needs both: a TCKN to check against the population registry, and) in Solidus's model. A DID to carry the resulting credential portably afterward.

Solidus today

Solidus has no live integration with NVİ, MERNİS, or KPS, and performs no authoritative TCKN-to-registry verification today. A Turkish-market KYC flow that includes an NVİ-style name/birthdate/TCKN match, the specific check several 2025 MASAK communiqués require of crypto-asset service providers, is a documented, planned feature, not a built one.

See also

e-Devlet is the government portal most Turkish TCKN-based identity confirmations run through in practice. KBS and BTK SIM Registration are two specific regulatory contexts that key off a person's TCKN. MASAK is the regulator whose 2025 rules made an NVİ-backed TCKN match a mandatory step for a specific sector. DID is the self-controlled identifier model this Lexicon's protocol layer builds on, worth contrasting directly against the TCKN's state-issued model.