Management Team
İsmail KOŞ
Chairman of the Board | Sworn-in Certified Public Accountant
İsmail KOŞ has over 30 years of professional experience in tax, audit and financial advisory services, and is the founder and Chairman of the Board of the Vezin Group. He specializes in tax advisory, corporate finance, mergers and acquisitions (M&A), valuation, transfer pricing, tax due diligence, independent audit and corporate governance advisory, and provides advisory services to numerous domestic and international companies operating across various sectors.
İsmail KOŞ graduated from the Faculty of Political Sciences at Ankara University in 1990 and began his professional career in the same year as a Tax Inspector at the Ministry of Finance. During his approximately ten-year tenure at the Ministry of Finance, he conducted tax inspections for domestic and foreign-capital companies operating in a wide range of sectors, including energy, construction, textiles, automotive, food, manufacturing, information technology, logistics, finance and petrochemicals, gaining significant experience in public sector audit.
Following his public sector career, Koş continued his career in the private sector, where he took an active role in national and international projects in areas such as tax planning, corporate restructuring, mergers and investment processes. Between 2003 and 2009, he served as a Board Member of the National Lottery Administration, and has a strong professional background combining both public and private sector experience.
As the founder of Vezin Sworn-in Certified Public Accountancy Inc. and Vezin Independent Audit Inc., İsmail KOŞ currently serves as Chairman of the Board and Partner within Vezin. Koş also holds the title of independent auditor and is proficient in English.
Süleyman Hayri Balcı
Partner | Sworn-in Certified Public Accountant / Independent Auditor
Süleyman Hayri BALCI is a Sworn-in Certified Public Accountant with extensive public and private sector experience in tax audit, international taxation and financial advisory services. He specializes in tax legislation, international tax treaties, transfer pricing and corporate tax advisory, with significant expertise particularly in international taxation and exchange of information processes.
BALCI graduated from the Faculty of Political Sciences at Ankara University in 1998 and began his professional career at the Board of Account Experts in 1999. Until 2009, he served as an Account Expert and Senior Account Expert at the Istanbul Group of the Board of Account Experts. During this period, he conducted tax inspections for numerous domestic and foreign-capital companies operating across various sectors.
Between 2007 and 2009, BALCI completed his master’s degree in Financial Economics at Boston University in the United States. He subsequently served at the Revenue Administration within the Department of EU and Foreign Affairs, first as Group Head and later as Head of Department. During this period, he played an active role particularly in the negotiation and implementation of Double Taxation Agreements, serving on behalf of Türkiye as both a delegation member and head of negotiation delegation in numerous international tax treaty negotiations.
BALCI is highly experienced in international tax cooperation and exchange of information. He took part in coordinating the preparatory work for the signing of the FATCA agreement in Türkiye and coordinated Türkiye’s participation in the OECD peer review processes in the field of exchange of information. He also represented Türkiye in various international meetings held under the auspices of the OECD, the United Nations and the Organisation of Islamic Cooperation.
In 2013, BALCI served as Assistant General Manager responsible for Financial Affairs at Boğaziçi Elektrik Dağıtım A.Ş. Later in the same year, he continued his professional activities in the private sector as a Sworn-in Certified Public Accountant. As one of the founding partners of Vezin Sworn-in Certified Public Accountancy Inc., BALCI is responsible for the management of the company’s Istanbul office and continues to provide services in the fields of tax advisory and audit.
Süleyman Hayri BALCI also holds the title of independent auditor and is highly proficient in English.
Ömer Duman
Partner | Sworn-in Certified Public Accountant
Ömer DUMAN is a Sworn-in Certified Public Accountant with extensive senior-level public administration experience in public finance, public administration, financial audit and financial management. He has held significant positions in the fields of public financial management, government accounting, financial audit and public finance, and has comprehensive expertise in financial management and audit processes across both the public and private sectors.
DUMAN graduated from the Department of Public Finance at the Faculty of Economics and Administrative Sciences of Dokuz Eylül University and completed his postgraduate studies at the Institute of Social Sciences of Gazi University. He began his professional career in 1989 as an Accounting Auditor at the General Directorate of Public Accounts of the Ministry of Finance. He later passed the entrance examination for the Board of Account Experts of the Ministry of Finance and was appointed as an Assistant Account Expert. In the following stages of his career, he held several important positions, including Account Expert, Senior Account Expert, Deputy Treasurer of Ankara and Head of Department at the General Directorate of Revenues.
In 2002, DUMAN served as an advisor to the Minister of Finance, Mr. Kemal Unakıtan. Between 2004 and 2011, he served as General Director of Public Accounts at the Ministry of Finance. During this period, he led significant initiatives aimed at improving public financial management, government accounting and financial control systems. In 2011, he was appointed as Chief Public Prosecutor of the Turkish Court of Accounts, and between 2016 and 2017, he served as Deputy Undersecretary of the Ministry of Finance.
Between 2017 and 2021, Ömer DUMAN served as a Member of the Bank Council and a Member of the Monetary Policy Committee of the Central Bank of the Republic of Türkiye, taking part in important policy processes in the fields of public finance, monetary policy and the financial system. During his public service career, he also served as Chairman of the Internal Audit Coordination Board, Chairman of the Government Accounting Standards Board, Member of the International Public Sector Accounting Standards Board (IPSASB), Member of the Audit Committee of the Central Bank of the Republic of Türkiye, and Board Member at various state economic enterprises.
During his tenure as General Director of Public Accounts, DUMAN received notable awards for projects he developed to promote the effective use of public resources. In 2005, he received first prize in the competition organized by the Prime Ministry on the effective use of resources, and in 2009, he received the e-TR Award for the “Gümkart” application.
In 2000, DUMAN spent one year in the United Kingdom conducting research and review studies. He has published various works in the fields of public finance and taxation. His books include “The Legal Nature and Taxation of Copyright Income,” “Accounting Audit and Reporting,” and “Offsetting and Refund of Tax in Income Tax, Corporate Tax, Value Added Tax and Special Consumption Tax.”
Holding Sworn-in Certified Public Accountant and Independent Auditor certificates, Ömer DUMAN joined the Ankara office of Vezin Sworn-in Certified Public Accountancy Inc. in 2021 as a Tax Partner. He is highly proficient in English.
Murat Özgür
Partner | Sworn-in Certified Public Accountant
Murat ÖZGÜR is a Sworn-in Certified Public Accountant with extensive public and private sector experience in tax audit, tax advisory and financial management. He specializes particularly in VAT and Special Consumption Tax refund processes, full certification services, the management of tax inspections and the resolution of tax disputes, and provides advisory services to many domestic and international companies operating across various sectors.
ÖZGÜR graduated from the Department of Business Administration at the Faculty of Economics and Administrative Sciences of Gazi University in 1996 and began his professional career at the General Directorate of National Property. He subsequently served as a Tax Auditor at the Ministry of Finance, where for approximately nine years he conducted tax audits of domestic and foreign-capital companies operating in various sectors, including energy, construction, textiles, automotive, food and manufacturing.
Between 2007 and 2011, ÖZGÜR served as Director of VAT, Special Consumption Tax and Agreements Implementation at the Ankara Tax Office Directorate. In 2011, he was appointed as a Tax Inspector and served as Deputy Group Head at the Tax Inspection Board. Between 2014 and 2017, he served as Head of Department at the Revenue Administration, and during the same period also worked for a time as Private Secretary to the Minister of Finance.
In 2017, Murat ÖZGÜR joined the Ankara office of Vezin Sworn-in Certified Public Accountancy Inc. as a Tax Partner. In addition to tax advisory and full certification services, he provides consultancy to taxpayers particularly on VAT and Special Consumption Tax refund processes, the management of tax inspections and the resolution of tax disputes.
ÖZGÜR has published articles in the fields of economics, law and taxation. He has also delivered numerous conferences, seminars and training programs, particularly on the VAT Law and its applications, within Sworn-in Certified Public Accountant and Certified Public Accountant chambers, chambers of commerce, trade unions and various non-governmental organizations.
Murat ÖZGÜR is highly proficient in English.
Ahmet Oruç
Partner | CPA | Independent Auditor
Ahmet ORUÇ is a Certified Public Accountant and Independent Auditor with experience in independent audit, financial advisory and corporate finance. He began his career in the field of independent audit and has worked with numerous national and international companies within the scope of audit, assurance and advisory services. Through his experience across various sectors, he has developed comprehensive expertise in financial reporting, audit and corporate finance processes.
Throughout his professional career, he has provided audit and advisory services to companies operating in the energy, manufacturing, services, construction, fast-moving consumer goods, oil and gas, mining, retail and technology sectors. He has taken part in significant projects particularly in areas such as company valuation, financial modelling, international financial reporting standards and initial public offering processes.
Ahmet ORUÇ has experience in the audit and assessment of financial statements prepared under different financial reporting frameworks, the performance of financial analyses in investment and growth processes, and the development of companies’ corporate finance processes. The work he carries out in this context contributes to enhancing companies’ financial transparency and enabling them to manage their investment processes more effectively.
A graduate of the Faculty of Business Administration at Bilkent University, Ahmet ORUÇ continues his professional career by providing audit and financial advisory services at international standards. With advanced proficiency in English, ORUÇ possesses the professional competence to take an active role in projects conducted on a global scale.
Ahmet ORUÇ joined Vezin in 2024 as an Independent Audit Partner and continues his work within the company in the fields of audit, financial advisory and corporate finance. Ahmet ORUÇ is highly proficient in English.
