Audit & Assurance
Financial statement audits, reviews, group reporting support and other assurance engagements designed to strengthen confidence in financial information.
Explore Audit & Assurance →Assurance • SOX • Accounting • Advisory • Tax • Transactions
Technical Excellence.
Practical Advice.
JCK Yoonsung LLP is an independent professional services firm delivering assurance, SOX compliance, accounting advisory, tax and transaction support to U.S. and multinational organizations.
Business insightPractical advice for complex decisions
Market perspectiveSupport for growing and global businesses
Technical excellenceDeep expertise across industries and services
Core services
Experienced support across assurance, controls, reporting, tax and transactions.
JCK supports finance teams, management, investors and boards with services designed around critical reporting obligations, control environments and business decisions. Our professionals combine technical accounting knowledge with practical execution.
SOX Compliance & Internal Controls
SOX readiness, framework design, risk and control matrices, design assessment, operating effectiveness testing, remediation and audit coordination.
Explore SOX & Controls →Accounting Advisory
US GAAP, IFRS and K-IFRS support for complex transactions, new standards, policies, reporting packages and close processes.
Explore Accounting Advisory →Tax Services
Federal, state and international tax compliance and planning for businesses, owners and multinational operations.
Explore Tax Services →Transaction Advisory
Financial due diligence, quality of earnings, deal readiness and transaction support for buyers, sellers and investors.
Explore Transaction Advisory →Financial Reporting Advisory
Revenue recognition, lease accounting, business combinations, consolidations and reporting process improvement.
Explore Financial Reporting →Why JCK
Technical depth, direct access and practical execution.
Clients engage JCK when they need experienced professionals who can understand the accounting issue, the control environment and the business context. Our approach emphasizes clear communication, senior attention and solutions that can be implemented.
Why organizations choose JCKDirect access to experienced partners and specialists
SOX, internal controls and assurance capabilities
US GAAP, IFRS and K-IFRS reporting expertise
Experience with U.S. and multinational organizations
Integrated accounting, tax and transaction perspective
Industries
Focused experience in the industries where our clients operate.
Our core industry experience spans consumer products, manufacturing, entertainment and media, financial services, and healthcare and life sciences. We also advise technology and investment-backed businesses as additional markets.
Consumer Products
Retail, e-commerce, beauty, lifestyle and consumer goods businesses.
Learn more →Manufacturing & Industrial
Inventory, costing, operations, supplier networks and global reporting environments.
Learn more →Entertainment & Media
Film, television, streaming, gaming, animation, digital content, licensing and royalty-driven businesses.
Learn more →Financial Services
Investment, lending, banking, asset management and regulated financial businesses.
Learn more →Healthcare & Life Sciences
Medical devices, life sciences, pharmaceuticals, healthcare technology and growing healthcare organizations.
Learn more →Technology
Software, platforms, digital products and high-growth technology companies.
Learn more →Private Equity
Transaction readiness, portfolio company reporting and finance transformation support.
Learn more →Leadership
Specialists who stay close to the work.
Our leadership team brings specialized experience across SOX and internal controls, IFRS and K-IFRS reporting, assurance, international tax and financial advisory.
Jaesoo Chung
Managing Partner focused on SOX implementation, control design, testing, assurance and cross-border reporting.
View profile →Yonjoo (YJ) Jung
Partner specializing in IFRS, K-IFRS, group reporting and assurance engagements.
View profile →Soonho (Sean) Kwon
Partner advising on U.S. federal, state and cross-border tax matters.
View profile →Yeongmin Jo
Partner supporting accounting advisory, financial reporting and transaction matters.
View profile →Insights
Technical perspectives for finance and business leaders.
Our insights focus on developments that affect financial reporting, controls, tax compliance and transactions. Explore practical perspectives on emerging standards and recurring business issues.
IFRS 18: preparing for presentation and disclosure changes
Key considerations for classification, management-defined performance measures and comparative presentation.
SOX readiness: building a sustainable control framework
How organizations can move from initial scoping and documentation to testing, remediation and ongoing compliance.
Revenue recognition: identifying judgment areas before year-end
A practical review of contract terms, performance obligations, variable consideration and cut-off risks.
Discuss a reporting, controls, tax or transaction matter with JCK.
Tell us about the issue you are working through. We will connect you with the appropriate assurance, SOX, accounting, tax or advisory professional.