Announcement on Re-appointment of Accounting Firm

Securities Code: 300691 Securities Abbreviation: United Optoelectronics Announcement No.: 2026-026

Zhongshan United Optoelectronics Technology Co., Ltd. Announcement on Re-appointment of Accounting Firm

The Company and all members of the Board of Directors guarantee the truthfulness, accuracy, and completeness of the information disclosed in this announcement, without any false records, misleading statements, or significant omissions.

Zhongshan United Optoelectronics Technology Co., Ltd. (hereinafter referred to as the "Company") held the seventh meeting of the fourth Board of Directors on April 21, 2026, and reviewed and approved the "Proposal on Re-appointing the Accounting Firm." The relevant situation is hereby announced as follows:

I. Basic Information on the Proposed Re-appointment of the Accounting Firm

(I) Institutional Information

1. Basic Information Lixin Certified Public Accountants LLP (hereinafter referred to as "Lixin") was founded by Dr. Pan Xulun, a renowned Chinese accounting scholar, in Shanghai in 1927. It was re-established in 1986 and became the first special general partnership accounting firm in China to complete its restructuring in 2010. Its registered address is in Shanghai, and its chief partner is Mr. Zhu Didi. Lixin is a member of the international accounting network BDO, has long been engaged in securities service business, held securities and futures business licenses before the implementation of the new Securities Law, possesses H-share audit qualifications, and is registered with the U.S. Public Company Accounting Oversight Board (PCAOB).

2. Personnel Information As of the end of 2025, Lixin had 300 partners, 2,523 certified public accountants, and a total of 9,933 employees. Among them, 802 certified public accountants had signed audit reports for securities service businesses.

3. Business Scale Lixin's business revenue for 2025 (unaudited) was RMB 5.00 billion, of which audit business revenue was RMB 3.672 billion and securities business revenue was RMB 1.505 billion. In 2025, Lixin provided annual report audit services to 770 listed companies, with audit fees of RMB 916 million. It served 102 listed companies in the same industry.

4. Investor Protection Capability As of the end of 2025, Lixin had accumulated RMB 171 million in its professional risk fund and purchased professional liability insurance with a cumulative insured amount of RMB 1.05 billion. This professional liability insurance can cover civil compensation liabilities arising from audit failures.