(i)        Payment schedule – accounting balances as of December 31, 2025

(ii)        Changes

33^rd Debenture issue

As of February 5, 2025, the Company raised R$ 3,700 million from the 33^rd issue of simple unsecured non-convertible debentures, in three series, with the following characteristics:

The proceeds from the issue will be allocated to the refinancing of financial commitments due in 2025, the recomposition and reinforcement of cash and the execution of investments for the Universalization of sanitation services.

In February 2025, interest rate swaps were contracted for the 2nd series, changing from IPCA + 7.5485% p.a. to CDI -0.34% p.a. and the 3rd series, changing from IPCA + 7.3837% p.a. to CDI -0.45% p.a.

The covenants agreed for the 33rd Issue of Debentures are:

Calculated quarterly, upon disclosure of quarterly information or annual financial statements:

- Net debt/adjusted EBITDA lower than or equal to 3.50;

- Adjusted EBITDA/paid financial expenses equal to or higher than 1.5;

Failure to comply with the financial indices above for at least two consecutive quarters, or for two non-consecutive quarters within twelve months (in which case the 30-day cure period does not apply), constitutes a default event that may lead to the early maturity of the Debentures, disposal of operating assets, termination of licenses, loss of concession or loss of the Company’s ability to execute and operate public sanitation services in areas of the São Paulo State which, individually or jointly during the term of the agreement, lead to a reduction of the Company’s net sales and/or service revenue of more than twenty- five percent (25%). The above limit will be calculated every quarter, taking into consideration the Company’s net operating income during the twelve (12) months before the end of each quarter and using the financial information disclosed by the Company.

Failure to comply with the limit above constitutes a default event that may lead to the early maturity of the Debentures.

22nd Debenture issue

In the period ended March 31, 2025, the Company paid the final amortization of the 22nd debentures issue, of R$ 191,184, of which R$ 180,237 in principal and R$ 10,947 in interest.

30th Debenture issue

In the period ended March 31, 2025, the Company paid the partial amortization of the 30th debentures issue, of R$ 148,571, of which R$ 125,000 in principal and R$ 23,571 in interest.

IDB INVEST 2020

In the period ended March 31, 2025, the Company fully pre-paid of the long-term tranche, in the amount of R$ 492,119, of which R$ 459,740 was principal and R$ 32,379 was interest. Additionally, on February 10, 2025, the medium-term tranche spread was renegotiated, changing from DI + 1.90% to DI + 0.90%, becoming effective as of February 18, 2025.

BNDES

In the period ended March 31, 2025, the Company paid the partial amortization of the agreements with BNDES, of R$ 90,845, of which R$ 70,994 in principal and R$ 20,042 in interest.

IFC 2025

In June 2025, the Company raised the amount of R$ 3,373 million from IFC, with the following characteristics:

The agreed covenants are: Calculated quarterly, upon disclosure of quarterly information or annual financial statements: - Net debt/adjusted EBITDA lower than or equal to 3.50; - Adjusted EBITDA/paid financial expenses equal to or higher than 2.35. They shall be maintained for two (2) consecutive quarters or not for any period of four (4) consecutive quarters. (no cure period applies to this hypothesis).

34th, 35th and 36th debenture issue

In the third quarter, the Company raised R$ 4,884 million from the issue of simple unsecured non-convertible debentures, in a single series, with the following characteristics:

Interest rate swaps were contracted for the 35th issue (changing from IPCA + 7.26% p.a. to DI - 0.32% p.a.) and 36th issue (changing from IPCA + 9.28% p.a. to DI +1.39% p.a.). With respect to the 36^th issue, of the total amount of R$ 2,815,700 million, R$ 2,765,7000 million have SABESP Lux, the wholly owned subsidiary, as the counterparty.

The agreed covenants for the 34th and 35th issues are:

Calculated quarterly, upon disclosure of quarterly information or annual financial statements:

- Net debt/adjusted EBITDA lower than or equal to 3.50;

- Adjusted EBITDA/paid financial expenses equal to or higher than 1.5;

Failure to comply with the financial indices above for at least two consecutive quarters, or for two non-consecutive quarters within twelve months (in which case the 30-day cure period does not apply), constitutes a default event that may lead to the early maturity of the Debentures, disposal of operating assets, termination of licenses, loss of concession or loss of the Company’s ability to execute and operate public sanitation services in areas of the São Paulo State which, individually or jointly during the term of the agreement, lead to a reduction of the Company’s net sales and/or service revenue of more than twenty- five percent (25%). The above limit will be calculated every quarter, taking into consideration the Company’s net operating income during the twelve (12) months before the end of each quarter and using the financial information disclosed by the Company. Failure to comply with the limit above constitutes a default event that may lead to the early maturity of the Debentures.

The 36th issue has no covenants.

Blue Senior Unsecured Notes (“Blue Bonds”)

In July 2025, the Company's wholly-owned subsidiary SABESP Lux priced the offer of senior unsecured notes in the total volume of US$ 500,000 thousand, guaranteed by Sabesp. The Blue Bonds were issued at a rate of 5.625% p.a., maturing in August 2030 and paying semi-annual interest. Interest rate swap transactions were entered into (swapping from 5.625% p.a. to IPCA + 9.28% p.a.). This transaction has the same terms as the 36th issuance mentioned above.

BID 1212:

In July 2025, the Company paid the final amortization of R$ 29,420, of which R$ 28,628 in principal and R$ 792 in interest.

28th debenture issue:

In July 2025, the Company paid the partial amortization of the 28th debentures issue, of R$ 509,085, of which R$ 444,100 in principal and R$ 64,985 in interest.

37th Debenture Issue

In the fourth quarter, the Company raised R$ 5,000 million from the issue of simple unsecured non-convertible debentures, in two series, with the following characteristics:

The 37th issue has no covenants.

JICA 2025

In October 2025, the Company entered into a financing agreement with the Japan International Cooperation Agency (JICA) in the total amount of Yen 30 billion. The financing has a twelve-year period with the following characteristics:

The agreed covenants are:

Calculated quarterly, upon disclosure of quarterly information or annual financial statements:

- Net debt/adjusted EBITDA lower than or equal to 3.50;

- Adjusted EBITDA/paid financial expenses equal to or higher than 2.35.

They shall be maintained for two (2) consecutive quarters or not for any period of four (4) consecutive quarters. (no cure period applies to this hypothesis).

The Company has lease agreements signed as Assets Lease. During the construction period, work costs are capitalized to contract assets against the lease liability.

The amounts payable for the right of use of assets are also recorded in this line. See Note 14 (e).

The table below shows the most restrictive covenants as of December 31, 2025.

Approximately 35% of the debt balance as of December 31, 2025 was subject to leverage limits.

As of December 31, 2025 and December 31, 2024, the Company met the requirements outlined by its borrowings and financing agreements.

The funds from financing contracted have specific purposes and are released for the execution of their respective investments, according to the execution of the works.

Below is detailed information on the borrowings and financing in force as of December 31, 2025. For a better understanding, the table below consolidates the instruments by financial institution, remuneration, currency of origin and linked guarantees:

Accounting policy

Borrowings and financing are initially recognized at fair value, at the time the funds are received, net of transaction costs and subsequently measured at amortized cost (except for liabilities irrevocably designated for measurement at fair value through profit or loss, as per note 20). Borrowings and financing are classified as current liabilities, unless the Company has an unconditional right to defer settlement of the liability for at least 12 months after the date of the statement of financial position.

The securities issued by the Company are not convertible into shares and are accounted for as borrowings.

Borrowing costs are interest and other charges incurred by the Company and arise from borrowing and financing agreements, including exchange variation.

Costs that are attributed to the acquisition, construction or production of an asset that necessarily require a substantial period to be ready for use or sale are capitalized as part of the cost of these assets. Other borrowing costs are recognized as expenses in the period in which they are incurred. Capitalization occurs during the period of construction of the asset, considering the weighted average rate of borrowings in force on the capitalization date.

In cases of borrowings or financing in foreign currency, the Company analyzes as if they were taken in national currency, limiting the capitalization of interest and/or exchange variation by the amount that would be capitalized if they were made in the local market in similar borrowing and financing lines.

The capitalization rate used in determining the amount of borrowing costs eligible for capitalization in the current year was 25%.