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Debt (Tables)

9 Months Ended

Sep. 30, 2025

Short-term Debt [Line Items]

Schedule of Other Short-term Borrowings

Information regarding commercial paper and borrowings under the single credit facility classified as short-term debt was as follows (dollars in millions):

September 30, 2025			Alliant Energy						IPL						WPL
Amount outstanding			$192						$—						$192
Weighted average interest rates			4.3%						N/A						4.3%
Available credit facility capacity			$1,108						$350						$208

			Alliant Energy												IPL												WPL
Three Months Ended September 30			2025						2024						2025						2024						2025						2024
Maximum amount outstanding (based on daily outstanding balances)			$372						$330						$78						$—						$297						$—
Average amount outstanding (based on daily outstanding balances)			$263						$197						$9						$—						$177						$—
Weighted average interest rates			4.5%						5.4%						4.6%						N/A						4.5%						N/A
Nine Months Ended September 30
Maximum amount outstanding (based on daily outstanding balances)			$741						$632						$141						$19						$297						$390
Average amount outstanding (based on daily outstanding balances)			$417						$320						$32						$1						$187						$87
Weighted average interest rates			4.6%						5.5%						4.6%						5.5%						4.5%						5.5%

IPL [Member]

Short-term Debt [Line Items]

Schedule of Other Short-term Borrowings

Information regarding commercial paper and borrowings under the single credit facility classified as short-term debt was as follows (dollars in millions):

September 30, 2025			Alliant Energy						IPL						WPL
Amount outstanding			$192						$—						$192
Weighted average interest rates			4.3%						N/A						4.3%
Available credit facility capacity			$1,108						$350						$208

			Alliant Energy												IPL												WPL
Three Months Ended September 30			2025						2024						2025						2024						2025						2024
Maximum amount outstanding (based on daily outstanding balances)			$372						$330						$78						$—						$297						$—
Average amount outstanding (based on daily outstanding balances)			$263						$197						$9						$—						$177						$—
Weighted average interest rates			4.5%						5.4%						4.6%						N/A						4.5%						N/A
Nine Months Ended September 30
Maximum amount outstanding (based on daily outstanding balances)			$741						$632						$141						$19						$297						$390
Average amount outstanding (based on daily outstanding balances)			$417						$320						$32						$1						$187						$87
Weighted average interest rates			4.6%						5.5%						4.6%						5.5%						4.5%						5.5%

WPL [Member]

Short-term Debt [Line Items]

Schedule of Other Short-term Borrowings

Information regarding commercial paper and borrowings under the single credit facility classified as short-term debt was as follows (dollars in millions):

September 30, 2025			Alliant Energy						IPL						WPL
Amount outstanding			$192						$—						$192
Weighted average interest rates			4.3%						N/A						4.3%
Available credit facility capacity			$1,108						$350						$208

			Alliant Energy												IPL												WPL
Three Months Ended September 30			2025						2024						2025						2024						2025						2024
Maximum amount outstanding (based on daily outstanding balances)			$372						$330						$78						$—						$297						$—
Average amount outstanding (based on daily outstanding balances)			$263						$197						$9						$—						$177						$—
Weighted average interest rates			4.5%						5.4%						4.6%						N/A						4.5%						N/A
Nine Months Ended September 30
Maximum amount outstanding (based on daily outstanding balances)			$741						$632						$141						$19						$297						$390
Average amount outstanding (based on daily outstanding balances)			$417						$320						$32						$1						$187						$87
Weighted average interest rates			4.6%						5.5%						4.6%						5.5%						4.5%						5.5%

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- Definition

Tabular disclosure of short-term debt arrangements (having initial terms of repayment within one year or the normal operating cycle, if longer) including: (1) description of the short-term debt arrangement; (2) identification of the lender or type of lender; (3) repayment terms; (4) weighted average interest rate; (5) carrying amount of funds borrowed under the specified short-term debt arrangement as of the balance sheet date; (6) description of the refinancing of a short-term obligation when that obligation is excluded from current liabilities in the balance sheet; and (7) amount of a short-term obligation that has been excluded from current liabilities in the balance sheet because of a refinancing of the obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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+ References

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