Sabesp

) % Employees at the end of each period 8,927 9,700 (773) (8.0) Employees - simple average 8,814 10,089 (1,275) (12.6) CAPITAL EXPENDITURSES In 1Q26, CapEx totaled R$ 3,728 mn, an increase of 30.8% compared to the same period of the previous year.

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

Borrowings and financing (Note 17); ix.

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

This risk arises from the possibility that the Company may incur losses due to exchange rate fluctuations that would impact liability balances of foreign currency-denominated borrowings and financing and related finance costs.

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

Part of the total financial debt in the amount of R$ 17,879,630 as of March 31, 2026 (R$ 10,632,252 as of December 31, 2025), is indexed to the U.

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

dollar, Yen and Euro with all other variables held constant, the effects on profit or loss before borrowing costs and taxes, for the three-month period ended March 31, 2026, would have been R$ 1,780,976 (R$ 305,835 for the three-month period ended March 31, 2025), upwards or downwards, excluding the effects of to the hedging instruments (Note 19).

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

Tariff adjustments of services provided do not necessarily follow the increases in the adjustments indices of borrowings, financing, and interest rates affecting indebtedness.

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

In 1Q26, investments totaled R$3.7 billion, a 31% increase versus 1Q25, supporting operational expansion and service quality improvements.

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

“Beyond the financial results, our priority continues to be delivering tangible advances in sanitation coverage and service standards.

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

Performance was driven by volume growth resulting from new connections (U-Factor targets fully attained), tariff gains and better collection, partially offset by the change in customer mix, with the expansion of consumers with access to subsidized rates².

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

As a result, Adjusted EBITDA increased by 26%, reaching R$3.8 billion in 1Q26, while Adjusted Net Income grew by 32%, totaling R$1.6 billion Sabesp invested R$3.7 bn in 1Q26, a 31% increase over the same period of the previous year, focusing on expansion projects directly aimed at meeting universalization targets.

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

(“EMAE”) On January 21, 2026, the Company acquired 29.9% of the total capital and 74.9% of the voting capital of EMAE, representing 11,009,550 (eleven million, nine thousand, five hundred and fifty) common shares of the company that focuses on the planning, construction, operation and maintenance of electricity generation systems, as well as their commercialization, operating under a concession regime.

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

Performance was driven by volume growth resulting from new connections (U-Factor targets fully attained), tariff gains and better collection, partially offset by the change in customer mix, with the expansion of consumers with access to subsidized rates².

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

The transaction was motivated by a combination of factors: Companhia de Saneamento Básico do Estado de São Paulo – SABESP Notes to the Financial Statements for the Period ended March 31, 2026 In thousands of reais, unless otherwise stated • Advanced water integration ensuring security of supply • Operational synergy between water and energy • Use of strategic window • Technical and regulatory feasibility This holistic approach reflects SABESP's strategy to strengthen its position as an essential services company in a context of climate challenges, growing demand and the need for better operational efficiency.

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026

Tariff adjustments of services provided do not necessarily follow the increases in the adjustments indices of borrowings, financing, and interest rates affecting indebtedness.

SEC original ↗Sabesp — Earnings release (6-K report)6-KMay 8, 2026