SECURITIES AND EXCHANGE COMMISSIONSEC FORM 17-C

CURRENT REPORT UNDER SECTION 17
OF THE SECURITIES REGULATION CODE
AND SRC RULE 17.2(c) THEREUNDER

1. Date of Report (Date of earliest event reported)

Dec 15, 2025

2. SEC Identification Number

A1996-11593

3. BIR Tax Identification No.

005-038-428-000

4. Exact name of issuer as specified in its charter

Manila Water Company, Inc.

5. Province, country or other jurisdiction of incorporation

Quezon City, Philippines

6. Industry Classification Code(SEC Use Only)

7. Address of principal office

MWSS Administration Building, No. 489 Katipunan Road, Balara, Quezon City Postal Code 1105

8. Issuer's telephone number, including area code

09171547921

9. Former name or former address, if changed since last report

n/a

10. Securities registered pursuant to Sections 8 and 12 of the SRC or Sections 4 and 8 of the RSA

Title of Each Class	Number of Shares of Common Stock Outstanding and Amount of Debt Outstanding
Common	2,601,499,272
Preferred (Unlisted)	3,563,756,068

11. Indicate the item numbers reported herein

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The Exchange does not warrant and holds no responsibility for the veracity of the facts and representations contained in all corporate disclosures, including financial reports. All data contained herein are prepared and submitted by the disclosing party to the Exchange, and are disseminated solely for purposes of information. Any questions on the data contained herein should be addressed directly to the Corporate Information Officer of the disclosing party.

Manila Water Company, Inc.MWC

PSE Disclosure Form 4-30 - Material Information/Transactions References: SRC Rule 17 (SEC Form 17-C) and
Sections 4.1 and 4.4 of the Revised Disclosure Rules

Subject of the Disclosure
Amendments to Audit Committee and Internal Audit Charters
Background/Description of the Disclosure
Please be informed that on December 15, 2025, our Board of Directors has ratified the Audit Committee’s resolutions approving the amendments to the Company’s Audit Committee and Internal Audit Charters aimed to strengthen governance, transparency, and align with the 2024 Global Internal Auditing Standards (“GIAS”). For the Audit Committee Charter, new requirements include annual charter reviews, confirmation of safeguards for non-audit roles, escalation processes for disagreements, and explicit approval of a risk-based internal audit plan aligned with organizational strategy. It also mandates reviewing annual quality assurance programs and external reviews every five years. For the Internal Audit Charter, enhancements include a clear mandate section, governance elements such as private sessions and independence confirmation, and Board approval of key plans and resources. Revisions broaden the purpose and scope to include organization-wide services (IT, fraud, ethics, compliance), unrestricted access, and improved quality assurance practices through ongoing monitoring and periodic external assessments. Please refer to the enclosed Amended Audit Committee and Internal Audit Charters.
Other Relevant Information
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