The Company requires all critical suppliers and contractors that have already passed the economic and sustainability risk assessment by using the Self-Assessment Questionnaire (SAQ) to have an audit on the economic, environmental, social, and governance topics at their workplaces (on-site ESG audit). The patterns and frequency of the on-site ESG audit depend on the risk level. The critical suppliers with very high and high risk will have an on-site audit as soon as possible; those at moderate risk will be audited once a year; and those at low risk will be audited every two years. The auditing items are set according to the Company’s criteria and the environmental management system (ISO 14001) standards and will be conducted by examining relevant documents and an on-site audit by the AMATA Procurement Working Committee.

In 2024, the Company had 21 critical suppliers required to undergo on-site ESG audit according to the established criteria. The Company successfully completed the audits for all 21 suppliers (100%).

The new supplier selection process includes reviewing the qualifications and past performance of suppliers and contractors to determine whether they meet the Company's requirements. All new suppliers are required to complete an ESG risk assessment using a self-assessment questionnaire prior to new supplier registration. If a passing score is achieved and no economic, social, or environmental risks are found, the new supplier will sign the Supplier Code of Conduct Acknowledgement and be registered as a new supplier. If a passing score is not achieved or there are risks, the supplier must develop and submit a preventive or corrective plan and implement it until the score is acceptable before it can be registered as a new supplier.

In 2024, there were 89 new suppliers. All of them passed the specified new supplier selection process (100%).

The Company is committed to conducting business fairly with its suppliers to support their liquidity and capital management, benefiting both parties. It adheres to all supplier agreements and commitments and treats all suppliers equitably. The Company has established policies for screening and evaluating suppliers, including manufacturers, contractors, and subcontractors, ensuring that these processes are effective, standardized, and uphold social responsibility. Additionally, the Company has implemented procurement policies and procedures and formed a procurement committee to ensure transparency, verifiability, and strict adherence to the selection processes.

Regarding supplier payments, the Company adheres to agreements and commitments by offering fair and appropriate trade credit durations, which fosters business collaboration and is crucial for sustaining long-term growth. A Credit Term Policy has been established, specifying payment to suppliers within 30-60 days through a banking channel. This method builds trust with suppliers and ensures timely payments within the policy framework. However, the actual payment period may vary due to specific business limitations, such as product types, service specifications, contract terms, and quality standards. Details on the average account payables days for purchasing products and services are as follows.

Furthermore, the Company emphasizes the development of suppliers and contractors throughout its supply chain, particularly those providing critical utility and industrial services, to mitigate social, environmental, and compliance risks. It encourages these partners to enhance their efficiency and align with the Company's standards by developing management systems and obtaining certifications in internationally recognized standards, such as ISO 9001, ISO 14001, ISO 17025, and OSHA 18000.