Direct Answer
Alliant Energy reports revenue across 3 business segments in its fiscal 2025 Form 10-K. Ipl is the largest, with $2.2 billion of revenue (51% of the total), followed by Wpl at $2.1 billion (47%).
How Does Alliant Energy Make Money?
No single line supplies a majority of revenue: the largest, Ipl, is 51%, which spreads Alliant Energy's exposure across several demand drivers. Between fiscal 2024 and 2025, Wpl grew fastest (+11.9%) and All Other slowest (-1.1%), so the revenue mix tilts toward Wpl while that gap lasts.
| Segment | FY2025 revenue | FY2024 revenue | Share of revenue | Change |
|---|---|---|---|---|
| Ipl | $2.2 billion | $2.0 billion | 50.6% | 7.9% |
| Wpl | $2.1 billion | $1.8 billion | 47.3% | 11.9% |
| All Other | $89 million | $90 million | 2.0% | -1.1% |
What the Segment Figures Do Not Show
The rows above add up to 100% of Alliant Energy's reported revenue for fiscal 2025; the difference is intersegment eliminations, corporate revenue or items the company reports outside its segments. Segment definitions are management's choice and change when a company reorganizes, in which case it restates prior years in the next filing, so a multi-year comparison should use the figures from a single filing. Revenue shows where sales come from, not where profit or cash is earned: a small segment can carry most of the margin.
Where These Numbers Come From
Every figure on this page is a value Alliant Energy reported in the segment note and revenue disclosures of its Form 10-K filed February 20, 2026 (accession 0000352541-26-000007), read from the SEC's Financial Statement Data Sets. The prior-year column is the comparative figure from that same filing, so it reflects any restatement for a change in segments. Category names are the company's own XBRL labels, lightly reformatted for reading.
Rows that only total other rows (for example a "Products" line beside the individual products) are left out so nothing is counted twice. This page is educational and describes reported history for fiscal 2025; it is not a forecast or a recommendation.
Frequently Asked Questions
What are Alliant Energy's business segments?
In its fiscal 2025 Form 10-K, Alliant Energy reports revenue for Ipl, Wpl and All Other.
Which part of Alliant Energy brings in the most revenue?
Ipl, with $2.2 billion of revenue in fiscal 2025, or 51% of the total.
Where does Alliant Energy report its segment results?
In the segment note to the financial statements in its Form 10-K, most recently filed February 20, 2026, alongside management's discussion of each segment's results.