Companhia de Saneamento Básico do Estado de São Paulo SABESP : Extraordinary Shareholders Meeting - 05/27/2024 - Call Notice

COMPANHIA DE SANEAMENTO BÁSICO DO ESTADO DE SÃO PAULO - SABESP

PUBLICLY HELD COMPANY

Corporate Taxpayer's ID (CNPJ): 43.776.517/0001-80

Company Registry (NIRE): 35.3000.1683-1

CALL NOTICE

EXTRAORDINARY SHAREHOLDERS' MEETING

Companhia de Saneamento Básico do Estado de São Paulo - Sabesp ("Company"), located at Rua Costa Carvalho, nº 300, in the City and State of São Paulo, hereby invites its Shareholders, according to paragraph 1 of article 5 of its Bylaws, to participate in the Company's Extraordinary Shareholders' Meeting ("ESM" or "Meeting"), to be held on May 27, 2024, at 11:00 a.m., in an exclusively digital format, through the Ten Meetings platform, according to Resolution 81 of the Brazilian Securities and Exchange Commission, of March 29, 2022, as amended ("CVM Resolution 81/22"), to resolve on the following agenda:

1. approve the amendment to the Company's Bylaws and its subsequent consolidation, relating to: (a) the amendment of article 3, to include the authorized capital, pursuant to the terms of article 168 of Federal Law 6.404/1976, allowing the Board of Directors to increase the Company's share capital up to the limit of 1,187,144,787 (one billion, one hundred and eighty-seven million, one hundred and forty-four thousand, seven hundred and eighty-seven) common, registered, book-entry shares with no par value, without requiring an amendment to the Bylaws, and (b) the inclusion of a new article 51, with the applicable rules on the possibility of the Company signing indemnity contracts with the members of the Board of Directors, Fiscal Council, Executive Board, statutory and non-statutory committees, managers and all other employees and legal representatives acting as delegates on behalf of the Company's administrators;

1. approve the complete reform of the Company's Bylaws, under a suspensive condition for the settlement of a public offering for the distribution of shares issued by the Company addressed in State Law 17.853/2023 ("Public Privatization Offering"), to include the provisions applicable to the Company after a privatization, including, among others, the creation of a special class of preferred shares exclusively held by the State of São Paulo, limitation of voting rights, change in the composition of the Company's Board of Directors, the election of members of the Board of Directors through the slate system, the creation of the Eligibility and Compensation Committee, the Sustainability and Corporate Responsibility Committee, and the Related Party Transactions Committee, and the requirement for a public takeover offering upon reaching a relevant shareholding; and

1. approve the conversion, under a suspensive condition for the settlement of the Public Privatization Offering, of 1 (one) common share held by the State of São Paulo in 1 (one) share of a special class exclusively held by the State of São Paulo, pursuant to article 17, paragraph 7, of Federal Law 6.404/1976, and in accordance with article 3 of State Law 17.853/2023; and

IV. substitute a sitting member of the Fiscal Council.

Shareholder Information:

The Meeting will be held exclusively online, according to CVM Resolution 81/22, and Shareholders are allowed to participate (i) in person or by a proxy, through the electronic platform at the time defined for the ESM, or (ii) by sending voting instructions before the ESM is held, through a Remote Voting Form ("BVD").

The rules and procedures for Shareholders' participation in the Meeting are detailed in the Manual for Participation in the Meetings, and the information about the matters to be resolved at the Meeting is detailed in the Management Proposal, both of which are available on the Company's Investor Relations website (ri.sabesp.com.br), and on the websites of B3 (www.b3.com.br)and the Brazilian Securities and Exchange Commission (www.gov.br/cvm).

1. Participation through the electronic platform

Shareholders who want to participate in the Meeting must pre-registeron the Ten Meetings Platform at the following linkhttps://assembleia.ten.com.br/907562746, until 11 a.m. of May 25, 2024, by selecting the "Register" option and uploading the documents detailed below:

• Photo ID document (RG, RNE, CNH, or professional class identification officially recognized in Brazil) of the Shareholder or, if participation by proxy, the photo ID of their legal representative;
• Statement issued by the institution providing bookkeeping services or by the custody institution, stating the number of shares held, dated no more than 3 (three) business days before the accreditation for participation in the Meeting; and, additionally,
• For investment fund shareholders: a copy of the consolidated fund regulations and the organizational documents or articles of incorporation of its administrator or manager, as applicable, together with corporate documentation proving the legal representation powers of the administrator or manager, as applicable (election of administrators and/or power of attorney, whereby in case of participation by proxy, the signature of the grantor does not need to be notarized);
• For corporate shareholders: a copy of the current corporate documents or articles of incorporation proving the legal representation powers of the Shareholder (election of administrators and/or power of attorney, whereby in case of participation by proxy, the signature of the grantor does not need to be notarized).

If Shareholders want to participate by proxy, they must register, in addition to the documents indicated above, the relevant power of attorney in the Ten Meetings platform, pursuant to legislation and the Manual for Participation in the Meetings.

It should be noted that the personal data and documents requested for accreditation and participation in the Meeting will be used exclusively for this purpose and will be processed according to article 7, item II, of Law 13,709/2018 (compliance with legal obligations), based on Brazilian Corporation Law and correlating regulations.

After analyzing the documents, the Shareholder or their proxies will receive a confirmation of registration on the Ten Meetings platform by email. Access to the ESM will be restricted to

Shareholders and/or their representatives or proxies accredited within the term defined by the Company, who will receive an individual invitation with specific instructions to access the digital platform.

1. Participation through the Remote Voting Form

If Shareholders decide to participate in the ESM through the remote voting form, they must

1. send filling instructions of the Remote Voting Form to service providers for the collection and transmission of instructions for filling out these documents (custody agents or bookkeeping agents of the shares issued by the Company), provided that such instructions are received within up to seven (7) days before the Meeting; or (b) send the Remote Voting Form directly to the Company; or (c) send the voting instructions via the Ten Meetings platform (through the link https://assembleia.ten.com.br/907562746), on the table "BDV", provided that the instructions are received within seven (7) days before the ESM (i.e. May 20, 2024), and any Remote Voting Forms received by the Company after this deadline will be disregarded.

The sending of the BVD to the custody agent or bookkeeping agent shall observe the applicable rules and procedures indicated by these service providers. BVD sent directly to the Company

• (i) mailing address, to Rua Costa Carvalho, nº 300, City and State of São Paulo (c/o the Superintendência de Captação de Recursos e Relações com Investidores department); (ii) by email to [e-mail]; or (iii) through the Ten Meetings platform, on the link https://assembleia.ten.com.br/907562746- must be accompanied by the documentation listed in item I above and detailed in the Manual for the Participation in the Meetings.

Shareholders who send their Remote Voting Forms may participate in the Meeting via the digital system. However, should they exercise their voting right in real time at the respective Meeting, their Remote Voting Forms will be fully disregarded, and the votes cast during the Meeting will be considered valid.

São Paulo, April 26, 2024.

Karla Bertocco Trindade

Chair of the Board of Directors