ALLIANT ENERGY CORP

NOTE 14. RELATED PARTIES

Service Agreements -Pursuant to service agreements, IPL and WPL receive various administrative and general services from an affiliate, Corporate Services. These services are billed to IPL and WPL at cost based on expenses incurred by Corporate Services for the benefit of IPL and WPL, respectively. These costs consisted primarily of employee compensation and benefits, fees associated with various professional services, depreciation and amortization of property, plant and equipment, and a return on net assets. Corporate Services also acts as agent on behalf of IPL and WPL pursuant to the service agreements. As agent, Corporate Services enters into energy, capacity, ancillary services, and transmission sale and purchase transactions within MISO. Corporate Services assigns such sales and purchases among IPL and WPL based on statements received from MISO. The amounts billed for services provided, sales credited and purchases for the three and nine months ended September 30 were as follows (in millions):

Net intercompany payables to Corporate Services were as follows (in millions):

ATC -Pursuant to various agreements, WPL receives a range of transmission services from ATC. WPL provides operation, maintenance, and construction services to ATC. WPL and ATC also bill each other for use of shared facilities owned by each party. The related amounts billed between the parties for the three and nine months ended September 30 were as follows (in millions):

WPL owed ATC net amounts of $13 million as of September 30, 2026 and $10 million as of December 31, 2025.

Transfer of Gas Generation Assets - In the third quarter of 2026, WPL sold gas generation assets to IPL for $57 million, in connection with IPL’s development of a natural gas-fired EGU within its service territory. The transaction price was equal to WPL’s carrying value of the assets, and as a result, no gain or loss was recognized on the transaction. The transaction price is reflected in “Construction and acquisition expenditures” within investing activities in IPL’s statement of cash flows and “Other investing activities” within investing activities in WPL’s statement of cash flows for the nine months ended September 30, 2026. For Alliant Energy, the intercompany transaction is eliminated upon consolidation and therefore is not reflected in Alliant Energy’s statement of cash flows.