About Us

Merkezi Kayıt Kuruluşu A.Ş. (MKK) serves as the Central Securities Depository and Trade Repository of the Turkish Capital Markets, offering its members depository, data, corporate governance, and investor services, along with global solutions.

MKK is the first licensed R&D Center in our capital markets and provides its services through software, systems, and platforms developed using its own internal resources.

DEPOSITORY SERVICES
Book-entry safekeeping of capital market instruments and electronic registration of agricultural products (ELÜS) are provided.

Capital Market Instruments Held in Dematerialized Form at MKK: 

• Equities (Listed at the Borsa Istanbul)
• Mutual Funds
• Exchange Traded Funds (ETF)
• Corporate Bonds
• Commercial Papers
• Bank Bills
• Corporate Warrants
• Covered Bonds
• Asset-Backed Securities
• Government Debt Securities (Investor Holdings)
• Government Lease Certificates
• Private Sector Lease Certificates
• Structured Debt Instruments
• Electronic Warehouse Receipts Based on Agricultural Products
• Real Estate Certificates
• Gold Backed Lease Certificates
• Gold Backed Bonds
• Convertible Bonds
• Foreign Exchange Government Certificates
• Foreign Exchange Government Bonds
• Mint Certificates

Central Depository Services:

• Investment/Custody account operations
• Issuer, securities issuance and corporate actions services
• Safekeeping of securities on beneficial owner basis and omnibus accounts 
• Settlement services for dematerialized securities
• Delivery and Control Services for physical securities that are provided on behalf of ICC
• Specialized Depository and Monitoring Service
• SWIFT services
• Services related to transactions on the Securities Lending Market and the Electronic Fund Trading Platform of Türkiye
• Services for Electronic Warehouse Receipts
• Services for Crowdfunding Platforms
• Services for Bearer Share Certificates

MKK’s Depository Services Products & Platforms:

• Central Dematerialized System (MKS)
• Elektronic Registry Center (e-ÜRÜN)
• Crowdfunding System (KFS)
• Bearer Shares Registry System (HPKS)
• Omnibus Global Accounts

DATA SERVICES
MKK provides data sharing services to the markets and to the public.

Authorized by the Capital Markets Board (CMB), MKK acts as the 'Trade Repository Institution' in Türkiye’s capital markets. Through the Electronic Trade Repository System (e-VEDO), it has established the infrastructure necessary for the reporting of derivative transactions executed both on organized markets and in the over-the-counter (OTC) markets. 

By collecting and sharing these reports with the relevant regulatory and supervisory authorities, e-VEDO facilitates the early detection of potential risks and supports the monitoring of systemic risk. This enables decision-makers to take data-driven and timely actions.

In addition, MKK shares aggregated market data with the public and relevant authorities.

MKK’s Data Services Products & Platforms:

• Electronic Trade Repository (e-VEDO)
• Investor Risk Monitoring System (YRTS)
• Data Analysis Platform (VAP)
• Real Estate Based and Developing Financial Instruments Information System (GEFAS)
• Indermediary Institutions MKK Data Analysis Platform (PUSULA)
• Capital Markets Data Bank (e-VERİ)

CORPORATE GOVERNANCE SERVICES
MKK enhances the corporate governance processes of companies.

In addition, MKK operates the Public Disclosure Platform (KAP), an electronic system through which disclosures required by capital markets and stock exchange regulations are electronically signed and submitted by the relevant parties, and then made available to the public. 

MKK also provides Electronic General Meeting System (e-GKS) for companies’ general assembly meetings and Electronic Board of Directors System (e-YKS) for their board processes, both of which serve thousands of users. 

e-GKS platform was recognized as one of the most advanced national systems for hybrid general meetings in the 2025 OECD report titled “General Meetings and Corporate Governance: Trends and Implications.”

MKK’s Corporate Governance Services Products & Platforms:

• Public Disclosure Platform (KAP)
• Electronic General Meeting System (e-GKS)
• Electronic Board of Directors System (e-YKS)
• Companies Information Portal (e-ŞİRKET)

INVESTOR SERVICES
Through MKK’s digital applications, investors can access information about their investments and perform their transactions quickly and securely in an electronic environment.

e-YATIRIMCI application provides investors with a single access point to all their investments, allowing them to monitor portfolio account balances and transactions across all investment firms, and to initiate blocking instructions.

With Crypto Asset Central Registry System (KVMKS) - whose development began in 2025 - investors will also be able to monitor their holdings in cryptocurrency markets.

MKK’s Investor Services Products & Platforms:

• Investor Information Center (e-YATIRIMCI)
• Crypto Asset Central Registry System (KVMKS)
• MKK Solution Center
• MKK Communication Center (MİM360)

GLOBAL SOLUTIONS SERVICES
MKK’s financial technology and infrastructure products are offered for use in both domestic and international markets. 

All our products and services are produced using national resources and in-house capabilities. In addition to contributing to Türkiye’s technology exports, MKK continues to strengthen the international recognition of its robust infrastructure.

Global Solutions Services Products & Platforms:

• MKK Real Estate Information Center Infrastructure Service (GABİM)
• MKK API Portal
• Indonesia Electronic General Meeting System (eASY.KSEI)
• Financial Leasing Contract Registration System (e-FTS)

International Relations and Omnibus Accounts Services
Since its establishment, MKK has built an effective communication and business network across international capital and financial markets, strengthening its brand image and positioning. 

Focusing its services on four main pillars — depository, trade repository and reporting, corporate governance, and investor services — MKK also contributes to the development of both local and international capital markets through the products and services developed within its R&D Center.

With its technology, extensive expertise, and deep experience, MKK is among the leading CSDs in terms of cooperation and collaboration agreements (Memorandum of Understanding, MoUs), signed with foreign CSDs. 

As of today, MKK is in formal relations with over 20 CSDs worldwide. Actively participating in working groups and conferences organized by major CSD Associations, ECSDA, AECSD, AMEDA, WFC and ISSA, MKK is among the few CSDs that hold active membership across these regional and global networks.

• MKK is a member of European Central Securities Depositories Association (ECSDA) and International Securities Services Association (ISSA) since 2006.
• MKK became a member of the Africa & Middle East Depositories Association (AMEDA) in 2014
• MKK is a member of the Association of Eurasian Central Securities Depositories (AECSD) since 2015
• MKK became a member of the Asia-Pacific CSD Group (ACG) in 2024
• MKK assumed the AECSD Presidency in 2023 and the WFC Presidency in 2025.
• AECSD & AMEDA İstanbul Summit was organized in October 2024, bringing together Central Securities Depositories from more than 40 countries at the İstanbul Financial Center for the first time.

After becoming a member of OeKB in 2010, MKK signed a sales agreement with Africlear Global in 2016 for the implementation of the Electronic General Meeting System (e-GKS) in Kenya and Nigeria, followed by another sales agreement with the Indonesian CSD, KSEI, in 2017.
 With the establishment of a direct link to Euroclear Bank, MKK significantly expanded its global reach. As MKK’s first foreign CSD member, Euroclear Bank provides its clients with direct access to the Turkish capital markets. Euroclear Bank itself maintains direct and indirect links with more than 55 markets worldwide.  
Following the first foreign central securities depository link established with Euroclear Bank's MKK membership, the National Deposit Center (MDM) of Azerbaijan became a member of MKK in 2021. Through the MDM omnibus account opened at MKK, investment institutions and investors from Azerbaijan can now directly carry out their settlement and custody operations for Turkish government debt securities.
In 2025, the membership of Clearstream Banking S.A. (Clearstream), the Luxembourg-based international central securities depository (ICSD), with MKK was completed, and a direct link was established. Through this connection, Clearstream now provides its clients in 59 countries with access to the Turkish capital markets.
The Kazakhstan Central Securities Depository (KCSD) has become MKK’s fourth foreign CSD member in 2025.  Through this link, investors in both Türkiye and Kazakhstan will be able to carry out the settlement and custody operations for government debt securities issued in either country via omnibus accounts opened at MKK and KCSD. This link has enabled market participants to access Turkish and Kazakh market instruments more efficiently and securely. 

Central Securities Depository 
Central Securities Depositories (CSDs) are among the most important post-trade institutions in capital markets. A CSD is an institution that performs at least one of the following core functions; operating a Securities Settlement System (SSS), performing the initial registration (issuance or notary service) of securities,  or providing central securities accounts maintenance (central safekeeping service).

An SSS is defined, in accordance with Article 2(i)(2) of the EU Settlement Finality Directive (98/26/EC), as a system in which securities transfer instructions are executed. The core element of the central depository function is the operation of a centralized system in which securities are issued, held in accounts — either on a participant or beneficial owner basis — traded, and in which the corresponding rights are recorded and maintained.

MKK is a central institution legally authorized to issue capital market instruments in dematerialized form, register them in accounts opened on a beneficial owner basis, and monitor the associated ownership rights.  The records kept in MKK’s books are legally binding. In other words, MKK operates a centralized system in which securities are issued, held in beneficial owner accounts, transferred, and where the respective rights are recorded and maintained. With this structure, MKK serves as the Central Securities Depository (CSD) of Türkiye.

History of Central Securities Depositories in Türkiye
The ISE Settlement and Custody, Inc., which was established by the ISE in 1992, was the authorized central settlement and depository institution conducting settlement of transactions in cash and securities on the ISE markets. In Türkiye, until 1995, Takasbank physically held stocks of listed companies in its vaults on a participant based immobilized system. After the financial crisis in 1994, as a result of the bankruptcy of some financial intermediaries, the ISE Settlement and Custody, Inc. was entrusted with the establishment of an investor (beneficial owner) based immobilized system with respect to the Capital Markets Board (CMB) decree dated 15 December 1994. The ISE Settlement and Custody, Inc. changed its name to the ISE Settlement and Custody Bank, Inc. (Takasbank) by receiving an investment banking license in 1997. During this period, stock certificates were continued to be physically issued and new certificates were printed for capital increases. However, publicly traded stocks of the ISE listed companies were immobilized at Takasbank first on a participant then on an investor basis. Therefore, the traditional valuable papers law and the physical system still existed legally for stocks and Takasbank continued its tasks accordingly until 28 November 2005.

Transition to the Dematerialized System and the Dematerialized System Law
The first step of the dematerialization reform for capital markets was taken with the addition of the Article 10/A to the Capital Market Law (CML). The Article 10/A of the CML brought about a significant change by annulling the former valuable papers law that was based on the physical certificates and introducing the legal framework for the dematerialized system in which MKK holds capital markets instruments and investor rights affixed on them in an electronic book-entryenvironment. MKK was founded in 2001 as the most important part of this reform.
The dematerialization process was started with mutual funds in April 2005, and on 28 November 2005 all publicly traded stocks on the ISE were fully dematerialized. Since 2005, all new capital market instruments have been issued in fully dematerialized form.

• The immobilized depository system that Takasbank continued to manage until 28 November 2005 was based on a CMB resolution, and our law did not attribute any legal impact concerning records held at Takasbank. In the physical system physical certificates constitute the legal basis whereas in the dematerialized system records held at MKK are deemed to constitute the legal basis. The Article 10/A of the CML removed the need for issuance of physical certificates on those securities and rights affixed on them that are deemed to be dematerialized by the CMB. Therefore, the former valuable papers system was discontinued for the new valuable rights system.
• The dematerialized system is a completely new legal discipline. The new system according to the Article 10/A introduced holding of shares and rights in an electronic environment by eliminating physical shares, and thus, eliminating the legal nature of the valuable paper. In this new system rights are entirely separated from papers. The dematerialized system removes many legal principles based on the valuable papers law. Besides bringing along new institutions the dematerialized system changed the legal nature of real rights to be established on shares.
• In the physical system that continued until 28 November 2005 only stocks that were traded on the ISE were physically held in Takasbank vaults. In the dematerialized system total capital, including all non-floating shares, are held in dematerialized form.
• At present all floating and non-floating shares of publicly traded companies, mutual funds, corporate bonds, commercial papers, warrants, covered bonds and asset backed securities are issued and held in MKK’s electronic book-entry system. Rights affixed on all dematerialized securities are reflected to MKK records and these records bear legal basis. In this regard, Takasbank’s functions before the transition to the dematerialized system and the functions attributed to MKK by the relevant regulations concerning the dematerialized system are entirely different. MKK is not a depository institution which holds physically issued stocks in global form as Takasbank did. MKK is a central depository institution where capital market instruments and the rights on them are held in dematerialized form, and whose records are attributed legal basis as per the depository functions assumed from the law. MKK has assumed all the functions of a CSD in this structure.
• It is clearly established in the regulations governing the dematerialized system that MKK’s records have full legal validity. The records maintained at MKK are declaratory rather than constitutive in nature, since claims asserted against third parties in relation to rights attached to dematerialized capital market instruments are based on the date of notification made by participants to MKK. It is not obligatory to carry out bilateral transactions on capital market instruments that are held at MKK through MKK for those transactions to be effectual for the parties. However, any notification that is made to MKK through its Central Dematerialized System (MKS) renders a transaciton the ability to be claimed against third parties. Therefore, as per the Article 10/A of the CML, it has been acknowledged that the notification (date) made to MKK has a legal basis in right entitlements due to transactions in capital market instruments. Another novelty brought about by the Article 10/A is that, in registering the transfer of shares to their books, issuers can take the records at MKK as basis without the need for any documentary proof. MKK assumes a function with regard to the assessment of an investor’s status against issuers besides acting as the Central Securities Depository. Beyond its role as the CSD, MKK also performs a “registry” function, assessing investors’ ownership status vis-à-vis issuers. This registry function, as defined in international post-trade terminology, enhances operational efficiency by integrating the CSD and registrar roles. In this respect, the legal character of the records held at MKK extends beyond pure safekeeping, encompassing registry functions alongside its traditional CSD responsibilities.
• The legal basis of the records held at MKK is further emphasised in the new Turkish Commercial Code which was adopted on 13 January 2011. By the Article no. 496 of the new Commercial Code it was decreed that in case the registered shares that are listed are sold on exchange, MKK will notify the companies about the identification of the transferor and the number of shares sold or will provide technical access to this information for those companies. Furthermore, the Articles no. 415-417 and 431 of the new Commercial Code, which regulates the procedures and principles of convening of general assemblies of joint stock companies, decrees that the list of participants to general assembly meetings shall be prepared according to the list of shareholders that will be received from MKK.
• The dematerialized system, which is primarily based on trust instead of documentary proof of right entitlements, cannot be insured in whole, and the inherent risks associated with this system cannot be covered by capital alone as the system carries substantial risks that cannot be fully indemnified. Therefore, by the Article no. 5 of the MKK regulation which was issued by the Council of Ministers, it was decreed that the CMB should appoint a member to the MKK board to act as the chairman of the board, through whom the CMB could effectively exercise its supervisory and regulatory roles. Furthermore, the Article no. 9 of the MKK regulation brings about additional requirements for the members of the MKK board of directors and its auditing board, and the MKK staff, preventing the hiring of personnel who were convicted of specific criminal offenses.
• As a further consequence of this framework, the Investor Protection Fund was administered by MKK during the initial phase of the dematerialized system to ensure investor protection.