UMC Announces Differences in Overseas Financial Reports Due to Inconsistent Accounting Principles Across Two Jurisdictions

1. Date of Occurrence: 115/04/30. 2. Financial Reporting Period: Q4 of FY114. 3. Accounting Principles Adopted for Securities Listed in Taiwan: International Financial Reporting Standards recognized by the FSC. 4. Differences in Financial Information for Securities Listed in Taiwan (in Chinese): Consolidated net profit attributable to owners of the parent is NT$41,716,249 thousand; basic and diluted earnings per share are NT$3.34 and NT$3.31, respectively; total assets are NT$578,996,009 thousand; total liabilities are NT$199,140,569 thousand; and equity attributable to owners of the parent is NT$379,768,265 thousand. 5. Accounting Principles Adopted for Securities Issued Overseas (in Chinese): International Financial Reporting Standards issued and effective by the International Accounting Standards Board. 6. Differences in Financial Information for Securities Issued Overseas (in Chinese): Consolidated net profit attributable to owners of the parent is NT$40,360,314 thousand; basic and diluted earnings per share are NT$3.30 and NT$3.27, respectively; total assets are NT$567,274,863 thousand; total liabilities are NT$201,362,691 thousand; and equity attributable to owners of the parent is NT$365,824,997 thousand. 7. Reason for Differences (in Chinese): The differences in accounting principles used for preparing financial reports in Taiwan and the United States are primarily due to the different recognition timing of corporate income tax on undistributed earnings and the accounting treatment of treasury stock. 8. Other Matters to be Noted: For detailed content, please refer to the company's 2025 English Annual Report (Form 20-F) filed with the U.S. Securities and Exchange Commission.