About us


Our goal is to support the efficiency and the sustainability in our client business operation and to solve the critical problems our clients face with based upon trustworthy and sound business relation.

The world has been complicatedly transforming with the digital economy in surge and the international regulations and systems have been rapidly changing along with it. In this circumstance, our role is to help get our clients to understand the international regulations and systems in complex and to run the efficient and sustainable business.

Thank you.


Don J. Oh, CPA, AA, MBA, MSc


• Certified Public Accountant (U.S.) (U.S. License# 36492)

• Foreign Certified Public Accountant (Korea) (Korea License# F00022)

• IRS Tax Return Preparer (RPO)

• IRS ITIN & EIN Acceptance Agent (AA)

• IRS EFTPS Batch Provider (TaxPro)

• FinCEN FBAR & BSA E-Filer (BSA)

• U.S. International Tax Consultant

• Tech Business Consultant

• QuickBooks Online Advanced Advisor

• University of Illinois at Urbana-Champaign, Master's Degree in Technology Management, Accountancy, and Corporate Governance and International Business

• Sogang University, Master's Degree in Finance


• Current) KORUS Tax Accounting / Business Consulting

• Prior) Accounting firm in Korea (International team)

• Prior) Accounting firm in the U.S.A

• Prior) Foreign-Invested Company (Global Tech Group)

Professional area


• U.S. Tax / International Tax

• U.S Company Accounting / Foreign-Invested Company Accounting

• Technology Advisory

Professional Networks

Provide various customized services through Accounting/Tax, Laws/Visa, and Tech Business professional networks.

• Accounting/Tax

• Laws/Visa

• Tech Business


• KORUS Tax Accounting / Business Consulting

• e-Mail: cpa@korusta.com

• Skype ID: live:cloudofficekorusta

• Tel. (KOR) +82-70-8680-9525

• Fax (KOR) +82-507-0333-9565