15.Related-Party Transactions

Related parties are primarily represented by AES and Siemens, their respective subsidiaries, other entities under common control, and other entities in which Siemens and AES have significant influence. As of March 31, 2026, AES Grid Stability holds 51,499,195 shares of Class B-1 common stock of Fluence Energy, Inc. and Siemens beneficially owns an aggregate of 51,499,195 shares of Class A common stock of Fluence Energy, Inc.

Sales and Procurement Contracts with Related Parties

The Company signs back-to-back battery-based energy storage solution and related service contracts with AES, Siemens, their respective subsidiaries, other entities under common control, and other entities in which Siemens and AES have significant influence (collectively referred to as affiliates) in relation to execution of the affiliates’ contracts with external customers and also signs direct contracts with affiliates. The Company also signs consortium agreements to partner with affiliates to deliver battery-based energy storage products and related service contracts to external customers. When performing our obligations pursuant to such contracts, we may, from time to time, enter into related change orders or settlements with our related parties and their affiliates.

The Company also provides consulting services to AES whereby Fluence will advise and in some cases provide support to AES on procurement, logistics, design, safety, and commissioning of certain of their projects. Revenue from consulting services is classified as “Revenue from sale of energy storage products and solutions” in the Company’s Disaggregation of revenue table in “Note 4 - Revenue from Contracts with Customers.” Revenue from the consulting services is primarily recognized ratably over time based on a project specific period of performance in which we expect the performance obligation to be fulfilled. For the three months ended March 31, 2026 and 2025, the Company recognized $0.1 million and $3.8 million in revenue from consulting services with AES, respectively. For the six months ended March 31, 2026 and 2025, the Company recognized $0.2 million and $5.4 million in revenue from consulting services with AES, respectively.

Revenue from contracts with affiliates is included in “Revenue from related parties” on the Company’s condensed consolidated statements of operations.

In addition, the Company purchases materials and supplies from its affiliates and records the costs in “Cost of goods and services” on the Company’s condensed consolidated statements of operations.

Service Agreements

For the three and six months ended March 31, 2026, the Company has received limited treasury services related to executing trades for derivative contracts from AES. The cost associated with this service is recorded in “General and administrative expenses” on the Company’s condensed consolidated statement of operations.

Guarantees

Fluence paid performance guarantee fees to its affiliates in exchange for guaranteeing Fluence’s performance obligations under certain contracts with Fluence’s customers, which are based on the affiliates’ weighted-average cost for bank guarantees and their per annum cost with a reasonable markup. These guarantees are provided pursuant to the Amended and Restated Credit Support and Reimbursement Agreement, dated June 9, 2021, with AES and Siemens Industry (the “Credit Support and Reimbursement Agreement”) whereby they may, from time to time, agree to furnish credit support to us in the form of direct issuances of credit support to our lenders or other beneficiaries or through their lenders’ provision of letters of credit to backstop our own facilities or obligations. The guarantee fees are included in “Costs of goods and services” on Fluence’s condensed consolidated statements of operations.

Refer to “Note 17 - Supply Chain Financing” for details of the related party guarantees associated with a supply chain financing program.

Balance Sheet Related Party Transactions

The Company’s condensed consolidated balance sheets included the following balances with related parties for the periods indicated:

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Receivables, deferred revenue, advances, accounts payable, accruals and provisions, and other current liabilities with related parties are unsecured and settlement of these balances occurs in cash. No provision has been made related to the receivables from related parties.

Statement of Operations Related Party Transactions

The following table presents the related party transactions that are included in the Company’s condensed consolidated statements of operations for the periods indicated:

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