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v3.25.3

Revenues | 9 Months Ended
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Sep. 30, 2025
Disaggregation of Revenue [Line Items] |
Revenues from Contracts with Customers | REVENUES Disaggregation of revenues from contracts with customers is provided for each reportable segment (IPL and WPL), as well as by customer class within electric and gas sales, as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Three Months Ended September 30 | 2025 |  | 2024 |  | 2025 |  | 2024 |  | 2025 |  | 2024
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $408 |  | $378 |  | $215 |  | $202 |  | $193 |  | $176
Retail - commercial | 282 |  | 239 |  | 192 |  | 153 |  | 90 |  | 86
Retail - industrial | 306 |  | 270 |  | 167 |  | 142 |  | 139 |  | 128
Wholesale | 51 |  | 58 |  | 11 |  | 19 |  | 40 |  | 39
Bulk power and other | 77 |  | 54 |  | 23 |  | 7 |  | 54 |  | 47
Total Electric Utility | 1,124 |  | 999 |  | 608 |  | 523 |  | 516 |  | 476
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 24 |  | 24 |  | 12 |  | 13 |  | 12 |  | 11
Retail - commercial | 13 |  | 13 |  | 7 |  | 7 |  | 6 |  | 6
Retail - industrial | 1 |  | 1 |  | 1 |  | 1 |  | — |  | —
Transportation/other | 13 |  | 11 |  | 7 |  | 6 |  | 6 |  | 5
Total Gas Utility | 51 |  | 49 |  | 27 |  | 27 |  | 24 |  | 22
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 9 |  | 9 |  | 9 |  | 9 |  | — |  | —
Other utility | 3 |  | 3 |  | 3 |  | 2 |  | — |  | 1
Total Other Utility | 12 |  | 12 |  | 12 |  | 11 |  | — |  | 1
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 23 |  | 21 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 23 |  | 21 |  | — |  | — |  | — |  | —
Total revenues | $1,210 |  | $1,081 |  | $647 |  | $561 |  | $540 |  | $499
| Alliant Energy |  | IPL |  | WPL
Nine Months Ended September 30 | 2025 |  | 2024 |  | 2025 |  | 2024 |  | 2025 |  | 2024
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $1,027 |  | $966 |  | $512 |  | $502 |  | $515 |  | $464
Retail - commercial | 705 |  | 616 |  | 462 |  | 385 |  | 243 |  | 231
Retail - industrial | 782 |  | 730 |  | 403 |  | 372 |  | 379 |  | 358
Wholesale | 148 |  | 147 |  | 39 |  | 45 |  | 109 |  | 102
Bulk power and other | 166 |  | 120 |  | 39 |  | 14 |  | 127 |  | 106
Total Electric Utility | 2,828 |  | 2,579 |  | 1,455 |  | 1,318 |  | 1,373 |  | 1,261
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 211 |  | 189 |  | 107 |  | 103 |  | 104 |  | 86
Retail - commercial | 106 |  | 92 |  | 49 |  | 48 |  | 57 |  | 44
Retail - industrial | 10 |  | 8 |  | 6 |  | 5 |  | 4 |  | 3
Transportation/other | 39 |  | 33 |  | 23 |  | 19 |  | 16 |  | 14
Total Gas Utility | 366 |  | 322 |  | 185 |  | 175 |  | 181 |  | 147
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 28 |  | 29 |  | 28 |  | 29 |  | — |  | —
Other utility | 9 |  | 7 |  | 8 |  | 5 |  | 1 |  | 2
Total Other Utility | 37 |  | 36 |  | 36 |  | 34 |  | 1 |  | 2
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 67 |  | 68 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 67 |  | 68 |  | — |  | — |  | — |  | —
Total revenues | $3,298 |  | $3,005 |  | $1,676 |  | $1,527 |  | $1,555 |  | $1,410
IPL [Member] |
Disaggregation of Revenue [Line Items] |
Revenues from Contracts with Customers | REVENUES Disaggregation of revenues from contracts with customers is provided for each reportable segment (IPL and WPL), as well as by customer class within electric and gas sales, as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Three Months Ended September 30 | 2025 |  | 2024 |  | 2025 |  | 2024 |  | 2025 |  | 2024
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $408 |  | $378 |  | $215 |  | $202 |  | $193 |  | $176
Retail - commercial | 282 |  | 239 |  | 192 |  | 153 |  | 90 |  | 86
Retail - industrial | 306 |  | 270 |  | 167 |  | 142 |  | 139 |  | 128
Wholesale | 51 |  | 58 |  | 11 |  | 19 |  | 40 |  | 39
Bulk power and other | 77 |  | 54 |  | 23 |  | 7 |  | 54 |  | 47
Total Electric Utility | 1,124 |  | 999 |  | 608 |  | 523 |  | 516 |  | 476
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 24 |  | 24 |  | 12 |  | 13 |  | 12 |  | 11
Retail - commercial | 13 |  | 13 |  | 7 |  | 7 |  | 6 |  | 6
Retail - industrial | 1 |  | 1 |  | 1 |  | 1 |  | — |  | —
Transportation/other | 13 |  | 11 |  | 7 |  | 6 |  | 6 |  | 5
Total Gas Utility | 51 |  | 49 |  | 27 |  | 27 |  | 24 |  | 22
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 9 |  | 9 |  | 9 |  | 9 |  | — |  | —
Other utility | 3 |  | 3 |  | 3 |  | 2 |  | — |  | 1
Total Other Utility | 12 |  | 12 |  | 12 |  | 11 |  | — |  | 1
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 23 |  | 21 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 23 |  | 21 |  | — |  | — |  | — |  | —
Total revenues | $1,210 |  | $1,081 |  | $647 |  | $561 |  | $540 |  | $499
| Alliant Energy |  | IPL |  | WPL
Nine Months Ended September 30 | 2025 |  | 2024 |  | 2025 |  | 2024 |  | 2025 |  | 2024
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $1,027 |  | $966 |  | $512 |  | $502 |  | $515 |  | $464
Retail - commercial | 705 |  | 616 |  | 462 |  | 385 |  | 243 |  | 231
Retail - industrial | 782 |  | 730 |  | 403 |  | 372 |  | 379 |  | 358
Wholesale | 148 |  | 147 |  | 39 |  | 45 |  | 109 |  | 102
Bulk power and other | 166 |  | 120 |  | 39 |  | 14 |  | 127 |  | 106
Total Electric Utility | 2,828 |  | 2,579 |  | 1,455 |  | 1,318 |  | 1,373 |  | 1,261
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 211 |  | 189 |  | 107 |  | 103 |  | 104 |  | 86
Retail - commercial | 106 |  | 92 |  | 49 |  | 48 |  | 57 |  | 44
Retail - industrial | 10 |  | 8 |  | 6 |  | 5 |  | 4 |  | 3
Transportation/other | 39 |  | 33 |  | 23 |  | 19 |  | 16 |  | 14
Total Gas Utility | 366 |  | 322 |  | 185 |  | 175 |  | 181 |  | 147
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 28 |  | 29 |  | 28 |  | 29 |  | — |  | —
Other utility | 9 |  | 7 |  | 8 |  | 5 |  | 1 |  | 2
Total Other Utility | 37 |  | 36 |  | 36 |  | 34 |  | 1 |  | 2
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 67 |  | 68 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 67 |  | 68 |  | — |  | — |  | — |  | —
Total revenues | $3,298 |  | $3,005 |  | $1,676 |  | $1,527 |  | $1,555 |  | $1,410
WPL [Member] |
Disaggregation of Revenue [Line Items] |
Revenues from Contracts with Customers | REVENUES Disaggregation of revenues from contracts with customers is provided for each reportable segment (IPL and WPL), as well as by customer class within electric and gas sales, as follows (in millions):
| Alliant Energy |  | IPL |  | WPL
Three Months Ended September 30 | 2025 |  | 2024 |  | 2025 |  | 2024 |  | 2025 |  | 2024
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $408 |  | $378 |  | $215 |  | $202 |  | $193 |  | $176
Retail - commercial | 282 |  | 239 |  | 192 |  | 153 |  | 90 |  | 86
Retail - industrial | 306 |  | 270 |  | 167 |  | 142 |  | 139 |  | 128
Wholesale | 51 |  | 58 |  | 11 |  | 19 |  | 40 |  | 39
Bulk power and other | 77 |  | 54 |  | 23 |  | 7 |  | 54 |  | 47
Total Electric Utility | 1,124 |  | 999 |  | 608 |  | 523 |  | 516 |  | 476
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 24 |  | 24 |  | 12 |  | 13 |  | 12 |  | 11
Retail - commercial | 13 |  | 13 |  | 7 |  | 7 |  | 6 |  | 6
Retail - industrial | 1 |  | 1 |  | 1 |  | 1 |  | — |  | —
Transportation/other | 13 |  | 11 |  | 7 |  | 6 |  | 6 |  | 5
Total Gas Utility | 51 |  | 49 |  | 27 |  | 27 |  | 24 |  | 22
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 9 |  | 9 |  | 9 |  | 9 |  | — |  | —
Other utility | 3 |  | 3 |  | 3 |  | 2 |  | — |  | 1
Total Other Utility | 12 |  | 12 |  | 12 |  | 11 |  | — |  | 1
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 23 |  | 21 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 23 |  | 21 |  | — |  | — |  | — |  | —
Total revenues | $1,210 |  | $1,081 |  | $647 |  | $561 |  | $540 |  | $499
| Alliant Energy |  | IPL |  | WPL
Nine Months Ended September 30 | 2025 |  | 2024 |  | 2025 |  | 2024 |  | 2025 |  | 2024
Electric Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | $1,027 |  | $966 |  | $512 |  | $502 |  | $515 |  | $464
Retail - commercial | 705 |  | 616 |  | 462 |  | 385 |  | 243 |  | 231
Retail - industrial | 782 |  | 730 |  | 403 |  | 372 |  | 379 |  | 358
Wholesale | 148 |  | 147 |  | 39 |  | 45 |  | 109 |  | 102
Bulk power and other | 166 |  | 120 |  | 39 |  | 14 |  | 127 |  | 106
Total Electric Utility | 2,828 |  | 2,579 |  | 1,455 |  | 1,318 |  | 1,373 |  | 1,261
Gas Utility: |  |  |  |  |  |  |  |  |  |  |
Retail - residential | 211 |  | 189 |  | 107 |  | 103 |  | 104 |  | 86
Retail - commercial | 106 |  | 92 |  | 49 |  | 48 |  | 57 |  | 44
Retail - industrial | 10 |  | 8 |  | 6 |  | 5 |  | 4 |  | 3
Transportation/other | 39 |  | 33 |  | 23 |  | 19 |  | 16 |  | 14
Total Gas Utility | 366 |  | 322 |  | 185 |  | 175 |  | 181 |  | 147
Other Utility: |  |  |  |  |  |  |  |  |  |  |
Steam | 28 |  | 29 |  | 28 |  | 29 |  | — |  | —
Other utility | 9 |  | 7 |  | 8 |  | 5 |  | 1 |  | 2
Total Other Utility | 37 |  | 36 |  | 36 |  | 34 |  | 1 |  | 2
Non-Utility and Other: |  |  |  |  |  |  |  |  |  |  |
Travero and other | 67 |  | 68 |  | — |  | — |  | — |  | —
Total Non-Utility and Other | 67 |  | 68 |  | — |  | — |  | — |  | —
Total revenues | $3,298 |  | $3,005 |  | $1,676 |  | $1,527 |  | $1,555 |  | $1,410

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