ACI WORLDWIDE, INC. (ACIW) stock intrinsic value fair value estimate & owner earnings analysis

ACI Worldwide sells the software that moves money for banks, merchants and billers. It reports two segments. Payment Software (2025 revenue $942 million) licenses and hosts the systems banks and merchants use to authorize card transactions, run real-time account-to-account payments and screen for fraud; its BASE24 card switch and newer ACI Connetic platform sit inside the core operations of large banks, where a replacement is a multi-year project that customers rarely undertake. Biller (2025 revenue $818 million) is largely the Speedpay bill-payment business bought from Western Union in 2019: utilities, insurers, lenders and government agencies use it to accept consumer payments, and most of its gross revenue ($555 million in 2025) is card interchange passed straight through to the card networks. After interchange and direct costs, Payment Software produced about $544 million of segment profit in 2025 and Biller about $141 million, so roughly four-fifths of the company's operating profit comes from Payment Software, not the roughly half our previous write-up described. No customer is 10% of revenue; the United States was 58% of 2025 sales. How we measure earnings. We start from operating cash flow, strip out year-to-year swings in working capital, subtract stock compensation as a real cost, and subtract the capital spending needed to stand still (property, equipment and capitalized software, about $30 to $45 million a year). Because this company carries about $825 million of bank debt, we now value the business before its lenders are paid, by adding back the cash interest it pays ($64 million in 2025), and then subtract the debt at the end. We also charge the cash rent on its leased offices (about $9 to $14 million a year), which otherwise slips through the working-capital adjustment. On that basis the business generated about $280 million in 2023, $333 million in 2024 and $338 million in 2025. We use the middle year, about $333 million, as the starting level, taking only 2023 onward because the September 2022 sale of the corporate online banking unit means earlier years describe a slightly different company. Two things we checked before relying on it: stock compensation nearly doubled to $71 million in 2025 (the 10-K attributes $18 million of the rise to general and administrative personnel), and the first half of 2026 ran at the same pace ($35.6 million), so we treat the higher level as permanent. And customer receivables have grown every year, because banks often pay for multi-year software licenses in installments; they have held steady at about 36% of revenue since 2022, so this is the working capital that growth requires rather than a collection problem. We therefore charge every case about $1.90 of added receivables for each extra dollar of annual cash flow it grows into. Growth. In 2025 the before-interest cash flow grew about 1.3% (per-share owner earnings grew about 5%, helped by buybacks). Our base case starts the next year at about $338 million, essentially flat on 2025, and only then allows growth. The growth we credit rests on two things already in evidence: a contracted and renewal backlog that ACI estimates at $7.26 billion over the next 60 months at the end of 2025, up 8% in a year, and revenue that has grown every year since 2020 at roughly 6% a year organically. We credit about half that pace. We do not credit new-product wins for ACI Connetic, share gains from bank modernization programs, margin expansion, or the September 2026 purchase of Cranium Ventures (a small card-switching technology firm, terms undisclosed), because none of those has yet produced results. We also do not credit a possible sale of the Biller segment: Reuters reported in July 2026 that ACI was exploring a sale valued around $1.5 billion, but nothing has been signed. If a sale happened near that price it would modestly add to our base value, since our own base case implies roughly $1.2 billion for that segment. Base case: cash flow of about $338 million in the first year, growing 3% a year through year 5 and 2% a year through year 10 (reaching about $420 million), then shrinking about 1% a year thereafter. The long tail rests on a structural fact: ACI's payment switches have run inside the world's banks for about five decades. The slow fade reflects Biller's thin economics after interchange (its net revenue grew only about 2% in 2025 even as gross revenue rose 13%) and the gradual migration of legacy card systems to newer platforms. After paying for the added receivables, the business is worth about $5,979 million; it owes about $708 million net ($825 million of term loans and revolver borrowings less about $117 million of cash beyond operating needs), leaving $5,271 million, or $51.83 per share. Bear case: a weak license year like 2023, when revenue grew only 2%, becomes the norm. Cash flow resets to about $290 million, the level the current company actually produced in 2023, and does not grow for ten years as Biller's interchange-heavy model stays under pressure and stock compensation stays elevated; after year 10 it shrinks 4% a year as legacy card-switch customers migrate away. The business is worth about $3,689 million, owes $708 million, and leaves $2,981 million, or $29.32 per share. Even here, cash flow covers the roughly $46 million annual interest bill about six times. Bull case: the backlog converts as it has recently and revenue keeps growing close to its five-year pace. Cash flow reaches about $350 million next year, grows 5% a year through year 5 and 3% through year 10 (about $493 million), and then holds flat on the strength of the installed bank base. The business is worth about $7,451 million, owes $708 million, and leaves $6,743 million, or $66.31 per share. The debt. All borrowings are floating-rate bank debt under a credit agreement maturing in February 2029, at 5.57% at the end of 2025, close enough to our 6% yardstick that we make no adjustment for its cost. Covenants allow net leverage up to 4.25 times and require interest coverage of at least 3 times; the company is far inside both, so refinancing risk is low in every case. What changed since our last estimate: we previously valued earnings after interest and did not subtract the debt, and we let per-share earnings compound at 5% to 7% a year indefinitely, largely on the back of buybacks. Now we value the business before its lenders, subtract the $708 million it owes, charge the receivables that growth requires, and credit only growth backed by the backlog and the company's own record. The higher starting level (before interest) partly offsets these changes, but the net effect lowers every case. What would make this estimate wrong: a large bank moving its card processing off BASE24 onto a competitor sooner than the backlog suggests would push results toward the bear case; a sale of Biller at or above $1.5 billion, or ACI Connetic winning major bank conversions, would push toward the bull case. Receivable collections are the figure to watch: if they stop keeping pace with revenue, reported earnings are running ahead of cash.