TSEC — Proxy Solicitation & Information Statement 2026

Apr 20, 2026

TSEC Corporation Notice of 2026 General Shareholders' Meeting

(Summary Translation)

The 2026General Shareholders' Meeting (the “Meeting”) of TSEC Corporation (the “TSEC”) will be held at 09:00 a.m., Thursday, May 22, 2026(shareholders attending starts from 8:30 am) at No. 335-12, Daxi Rd., Pingtung City, Pingtung County 90093, Taiwan (R.O.C.) (TSEC Pingtung Plant).

. Agenda as follows:

1. Report Matters

• (1) 2025 Business Report.

• (2) Audit Committee's Review of the 2025 Year-End Report.

• (3) The company's accumulated losses have reached half of its paid-in capital.

• (4)Director Remuneration Policy.

1. Matters to Be Ratified

• (1) Ratifying the 2025 Business Report and each financial statement.

• (2) Ratifying the 2025 Profit and Loss Appropriation.

1. Discussions

• (1) Amend certain provisions of The Company's Articles of Incorporation.

1. Extemporary Motions

• . In accordance with Article 165 of the Company Act, transfer of shares of the Company shall be suspended from March 24, 2026 through May 22, 2026.

• . If the matters convened for this shareholders’ meeting include any proposals whose main contents are required to be listed under Article 172 of the Company Act, please visit the Market Observation Post System (https://mops.twse.com.tw), click “Single Company / Electronic Document Download / Annual Report and Shareholders' Meeting Information" enter our company code and annual inquiry.

• . In addition to the above announcement, this letter will also attach a copy of the “Notice of Attendance” and “Proxy Statement” for the shareholders meeting. If you are present in person, please sign or stamp the "Notice of Attendance" and bring it to the meeting on the day of the meeting(please Do Not return by mail). In case of shareholder’s proxy is present, please fill in the relevant information of the proxy on the "Proxy Statement" and sign or stamp in person, and mail the statement back to TSEC stock agency (First Securities Inc.) no later than five days before the meeting. The shareholding agency of TSEC will prepare

the attendance card and mail it back to the proxy holder to attend the meeting. (When a shareholder or proxy attends the shareholders meeting, please bring along the identification for reference).

• . If shareholders solicit proxies, TSEC will compile a summary statement of proxy solicitation before April 21, 2026 and disclose the content on the website http://free.sfi.org.tw to access the "free inquiry system of power of attorney" and input the securities code: 6443 for shareholders to enquire.

• . Shareholders of this shareholder meeting can exercise their voting rights electronically. Please log in to the “Shareholders Meeting Electronic Voting Platform” of Taiwan Central Depository and Clearing House Co., Ltd. to vote. The operation is in accordance with the relevant instructions. [Address: http://www.stockvote.com.tw] during the period of exercise from April 22, 2026 to May 19, 2026 .

• . The proxies shall be tallied and verified by the share agent department of First Securities Inc. To Shareholder Board of Directors of TSEC Corporation.

To Shareholder

Board of Directors of TSEC Corporation