We are a full service accounting firm specialized in international tax and business consulting, designed to deliver the same services that Fortune 500 companies receive from the Big Four firms. Our focus is to put these services within reach of all-size businesses as well as federal, state and local government agencies. To meet our premise we have assembled an elite team of partners, professional advisors and foreign correspondents, who come from large firms that assist companies in the Fortune 500 environment. We have streamlined processes, identifying and eliminating the most costly and unnecessary infrastructures to optimize investments and help your business grow in size, scope and revenue at a fraction of the cost associated with traditional firms.


Providing a full array of financial consulting and public accounting services with added value


Being The Public Accounting and Financial Consulting Firm of Excellence


Honesty, Excellence, Confidence, Respect, Identity, Loyalty, Transparency, Commitment, Productivity, Integrity, Progress

Nestor Guillen

Nestor L. Guillén, Founder & Partner

Mr. Guillén is a recognized financial expert having spent the last 30 years in accounting advisory, tax planning, tax consulting, mergers and acquisitions, tax and financial due diligence, and cross border transactions for individuals and corporations in USA, Latin America and the Caribbean. Mr. Guillén is a founder partner of Globalbiz Tax & Business Consulting, and Guillen Serrano & Associates in Miami, besides being Founder and Managing Partner of Grant Thornton in Venezuela, was the Executive Director of Grant Thornton LLP’s Latin America Tax Gateway, based in Miami, and served on the Latin American Executive Committee of Grant Thornton International. Additionally, Mr. Guillen served on numerous Boards including the British American Chamber of Commerce of Florida, the International Committee of the Greater Miami Chamber of Commerce and several bi-national Chambers of Commerce in South Florida. Mr. Guillen is licensed as a CPA in the states of Florida and Georgia, USA and in Venezuela; he is a graduate accountant from the Universidad del Zulia, Venezuela, He has a specialized degree in International Businesses from the Universidad Metropolitana, Caracas, Venezuela, and a MBA graduate with Distinction from Keller Graduate School of Business at Devry University in USA.

Gustavo Serrano

Gustavo Serrano, Founder & Partner

Gustavo Serrano has a wide career with over 25 years experience, since the beginning has worked as a tax advisor in different Legal Firms recognized even as Executive Vice President of Tax Affairs at Private and Commercial banks. He is a Partner Guillen, Serrano & Associates and manages as well the operation in Venezuela of the affilaited firm Serrano Cid & Asesores. Mr. Serrano has authored / co-authored several books regarding tax matters. He has been a Professor of Tax Law at the Universidad Católica Andrés Bello, and at the "Institute for Professional Development for the Association of CPAs of the Federal District and Miranda State in Venezuela. (IDEPROCOP)". He has also been a member of the "Tax Standards Committee for the “Federación de Colegios de Contadores Públicos de Venezuela", the "Asociación Venezolana de Derecho Financiero (ASOVEDEFI)", the "Colegio de Contadores Públicos del Distrito Capital", the "IFA (International Fiscal Association)" and the "Instituto Colombiano de Derecho Tributario (ICDT)". Prior to founding in 2003 his own Tax and Business Consulting firm, Mr. Serrano was a Tax Consultancy Partner at the law firm Torres Plaz & Araujo, and an Executive Vice-President for Tax Affairs at Interbank C.A., Banco Universal. He has received several awards including Order of the Public Accountant from the “Colegio de Contadores Públicos del Estado Miranda”, the Order of Merit from the “Colegio de Contadores Públicos del Distrito Capital”, and the Order of Public Accountant from the “Federación de Colegios de Contadores Públicos de Venezuela”. Serrano has achieved honorable mentions in his degrees, among which are; a Degree in Accounting, Andres Bello Catholic University in Venezuela 1996, Bachelor of Science Degree in Business Administration, Atlantis University, EEUU 2012. Diploma in International Contracts and Litigation, Arbitration and American Law, Florida International University, USA 2014. Also He has a specialized degree in Tax Laws, Andres Bello Catholic University, Summa Cumlaude, 2002. A degree in International Taxation, Santiago de Compostela University, Spain 2009, and a Master of Business Administration, Atlantis University, USA 2014.


Service Name


Financial Reporting. Private companies. Government entities. Internal Controls.

Service Name

Accounting & Tax

Small business. Payroll processing and reporting. Tax Planning, Tax Filing. Tax Problem Solutions.

Service Name

International Tax

Corporate and individual, International structuring, New markets tax research and projection, OVDP and streamlined procedures, compliance in foreign jurisdictions.

Service Name

Business Consulting

Cash Flow Management. New Business. Strategic Business Plans. Mergers and Acquisitions.