Whistleblowing and Complaints

SUSCO Public Company Limited (the “Company”) is committed to conducting its business with honesty, transparency, and responsibility to all stakeholders. The Company therefore provides channels for receiving whistleblowing reports and complaints so that employees, shareholders, customers, business partners, communities, and other stakeholders can report information about acts that may be improper, or matters that may affect the rights and interests of stakeholders.

The Company has assigned the Audit Committee to receive and screen the details of each report before conducting an investigation together with the relevant parties according to the nature of the matter, and to present the matter to the Board of Directors for acknowledgement or consideration as appropriate.

Scope of Matters That Can Be Reported

Stakeholders may report whistleblowing information or complaints relating to the Company on the following matters:

• Violation of laws and the Company’s guidelines, such as acts that may not comply with laws, regulations, the business code of conduct, or policies established by the Company
• Fraud and corruption, such as embezzlement, fraud, giving or receiving bribes, soliciting benefits, or using one’s position for wrongful gain
• Inappropriate conduct by directors, management, or employees that may affect the Company or stakeholders
• Infringement of rights or unfair treatment of employees, customers, business partners, communities, or other groups of stakeholders
• Other matters related to the Company’s operations that may cause damage or warrant fact-finding

Channels for Reporting Whistleblowing Information and Complaints

Whistleblowers may choose whichever channel is convenient, as follows:

Information That Should Be Reported

To enable the Company to conduct an appropriate fact-finding investigation, whistleblowers should provide as much of the following information as they know:

• The matter or conduct to be reported, together with details of what happened
• The date, time, and place the incident occurred, or the period during which it was discovered
• The name of the person or unit involved, if known
• Supporting documents, photographs, or evidence, if any
• Name and contact channel, if the whistleblower wishes the Company to request further information

A whistleblower who is concerned that disclosing their identity may affect them may report the matter anonymously by letter or through the complaint box. Providing sufficient details and evidence will help the Company consider and investigate the reported matter.

Procedures for Receiving and Considering Complaints

1. Receipt of the Report

The Company receives reports through the channels specified above. For the complaint box, representatives of the Internal Audit Office and the Corporate Secretary Office jointly open the box twice a month and forward the reports received into the Company’s consideration process.

2. Screening of the Matter

The Audit Committee considers the details of the matter to assess the nature of the complaint and determine the relevant parties to jointly investigate the facts as appropriate.

3. Fact-Finding Investigation

• For matters that may involve fraud or corruption: the Audit Committee refers the matter to the Anti-Corruption Working Group to investigate the facts and report the results back to the Audit Committee as quickly as possible
• For other matters: the Audit Committee considers the matter together with the relevant units
• For complaints from employees: the Company considers the matter under the above procedures or under the Company’s regulations, as the case may be

Receiving a complaint is the starting point of the fact-finding investigation. The Company will consider the information and the parties involved fairly before reaching a conclusion.

4. Consideration and Reporting

The Audit Committee considers the results of the investigation and the course of action according to the nature of the matter before presenting it to the Board of Directors for acknowledgement or consideration as appropriate. The independent directors serving on the Audit Committee are informed of complaints through the Audit Committee’s consideration process.

5. Follow-Up, Prevention of Recurrence, and Remedy

If the investigation finds that the complaint is substantiated, the Company will consider corrective action according to the nature and severity of the matter, monitor the results of that action, and consider improving relevant procedures or control measures to prevent recurrence. If any party has been affected, the Company will consider a remedy based on the facts and as appropriate.

Confidentiality and Protection of Whistleblowers and Complainants

The Company protects whistleblowers or complainants from unfair treatment as a result of making a report. Anyone concerned that disclosing their identity may affect them may choose to remain anonymous through the channels specified above.

The Company will keep the information of the whistleblower, information providers, and related parties with care, and disclose it to relevant parties only to the extent necessary for the fact-finding investigation and the performance of duties, having regard to fairness to all parties and the protection of personal data.

Whistleblowing and Complaints Performance for 2025

In 2025, the Company had no whistleblowing reports or complaints through the channels established by the Company. Accordingly, there were no matters pending at year-end and no cases requiring remedy for parties affected by such complaints.

Improvements to Prevent Recurrence and Remedy in 2025

Because the Company had no whistleblowing reports or complaints through the established channels in 2025, there were no cases arising from complaints requiring improvement to prevent recurrence or to remedy affected parties. Nonetheless, the Company continues to maintain its measures to prevent wrongdoing on an ongoing basis.

Measures to Prevent Wrongdoing

• Establish and communicate the Anti-Corruption Policy and the Business Code of Ethics as guidelines for directors, management, and employees
• Provide multiple channels for receiving whistleblowing reports and complaints so that stakeholders can report matters to the Company
• Assign the Audit Committee to oversee the receipt of complaints, and assign the Anti-Corruption Working Group to investigate facts in matters related to corruption
• Assess corruption risk at least once a year and review risk management measures to ensure their effectiveness
• Communicate the Anti-Corruption Policy to directors, management, employees, and stakeholders in accordance with the Company’s guidelines