Form 10-K - Annual report [Section 13 and 15(d), not S-K Item 405]:
SEC Accession No. 0000352541-26-000007
Filing Date
2026-02-20
Accepted
2026-02-20 14:58:00
Documents
157
Period of Report
2025-12-31

Document Format Files

Seq Description Document Type Size
1 10-K lnt-20251231.htm   iXBRL 10-K 5644326
2 EX-4.1C lnt1231202510-kex41c.htm EX-4.1C 78784
3 SUMMARY OF COMPENSATION AND BENEFITS FOR NON-EMPLOYEE DIRECTORS lnt1231202510-kex1012.htm EX-10.12 6979
4 SUBSIDIARIES OF ALLIANT ENERGY lnt1231202510-kex211.htm EX-21.1 3585
5 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM FOR ALLIANT ENERGY lnt1231202510-kex231.htm EX-23.1 2277
6 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM FOR IPL lnt1231202510-kex232.htm EX-23.2 2048
7 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM FOR WPL lnt1231202510-kex233.htm EX-23.3 2046
8 CERTIFICATION OF THE CEO FOR ALLIANT ENERGY lnt1231202510-kex311.htm EX-31.1 9385
9 CERTIFICATION OF THE CFO FOR ALLIANT ENERGY lnt1231202510-kex312.htm EX-31.2 9406
10 CERTIFICATION OF THE CEO FOR IPL lnt1231202510-kex313.htm EX-31.3 9379
11 CERTIFICATION OF THE CFO FOR IPL lnt1231202510-kex314.htm EX-31.4 9412
12 CERTIFICATION OF THE CEO FOR WPL lnt1231202510-kex315.htm EX-31.5 9364
13 CERTIFICATION OF THE CFO FOR WPL lnt1231202510-kex316.htm EX-31.6 9410
14 WRITTEN STATEMENT OF CEO AND CFO PURSUANT TO 18 U.S.C. 1350 FOR ALLIANT ENERGY lnt1231202510-kex321.htm EX-32.1 4361
15 WRITTEN STATEMENT OF CEO AND CFO PURSUANT TO 18 U.S.C. 1350 FOR IPL lnt1231202510-kex322.htm EX-32.2 4344
16 WRITTEN STATEMENT OF CEO AND CFO PURSUANT TO 18 U.S.C. 1350 FOR WPL lnt1231202510-kex323.htm EX-32.3 4342
22 GRAPHIC lnt-20251231_g1.jpg GRAPHIC 334542
23 GRAPHIC lnt-20251231_g2.jpg GRAPHIC 13819
24 GRAPHIC lnt-20251231_g3.jpg GRAPHIC 14729
25 GRAPHIC lnt-20251231_g4.jpg GRAPHIC 12119
26 GRAPHIC lnt-20251231_g5.jpg GRAPHIC 12016
  Complete submission text file 0000352541-26-000007.txt   45212365

Data Files

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17 XBRL TAXONOMY EXTENSION SCHEMA DOCUMENT lnt-20251231.xsd EX-101.SCH 124472
18 XBRL TAXONOMY EXTENSION CALCULATION LINKBASE DOCUMENT lnt-20251231_cal.xml EX-101.CAL 103595
19 XBRL TAXONOMY EXTENSION DEFINITION LINKBASE DOCUMENT lnt-20251231_def.xml EX-101.DEF 1241130
20 XBRL TAXONOMY EXTENSION LABEL LINKBASE DOCUMENT lnt-20251231_lab.xml EX-101.LAB 1347480
21 XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE DOCUMENT lnt-20251231_pre.xml EX-101.PRE 1360396
159 EXTRACTED XBRL INSTANCE DOCUMENT lnt-20251231_htm.xml XML 15239775
Mailing Address 200 FIRST ST SE ALLIANT ENERGY TOWER CEDAR RAPIDS IA 52401
Business Address 200 FIRST ST SE ALLIANT ENERGY TOWER CEDAR RAPIDS IA 52401 3193984411
INTERSTATE POWER & LIGHT CO (Filer) CIK: 0000052485 (see all company filings)

EIN.: 420331370 | State of Incorp.: IA | Fiscal Year End: 1231
Type: 10-K | Act: 34 | File No.: 001-04117 | Film No.: 26658900
SIC: 4931 Electric & Other Services Combined
(CF Office: 01 Energy & Transportation)

Mailing Address 4902 N BILTMORE LANE SUITE 1000 MADISON WI 53718-2148
Business Address 4902 NORTH BILTMORE LANE SUITE 1000 MADISON WI 53718-2148 608-458-3311
WISCONSIN POWER & LIGHT CO (Filer) CIK: 0000107832 (see all company filings)

EIN.: 390714890 | State of Incorp.: WI | Fiscal Year End: 1231
Type: 10-K | Act: 34 | File No.: 000-00337 | Film No.: 26658901
SIC: 4931 Electric & Other Services Combined
(CF Office: 01 Energy & Transportation)

Mailing Address 4902 NORTH BILTMORE LANE SUITE 1000 MADISON WI 53718-2148
Business Address 4902 NORTH BILTMORE LANE SUITE 1000 MADISON WI 53718-2148 608-458-3311
ALLIANT ENERGY CORP (Filer) CIK: 0000352541 (see all company filings)

EIN.: 391380265 | State of Incorp.: WI | Fiscal Year End: 1231
Type: 10-K | Act: 34 | File No.: 001-09894 | Film No.: 26658899
SIC: 4931 Electric & Other Services Combined
(CF Office: 01 Energy & Transportation)