A software platform signs its 400th merchant and looks at the payments line on its own books for the first time. The revenue share from the incumbent processor covers a small share of what those merchants generate in card fees every month. The question that follows is narrow. If you move that volume in-house, what does it cost per month, per transaction, and per merchant approved?
Most pricing pages answer in ranges. Published rates get closer to a working number, though that number moves with card mix, average ticket, and volume tier.
Subscription First, Markup Second
Finix prices on interchange-plus. The merchant pays the interchange rate the card network sets, a fixed per-transaction fee on top of it, and a monthly subscription. The starter plan sits near $250 per month for businesses processing under $1 million in annual volume. PCI compliance and base fraud tools come inside that tier rather than as separate line items. A Finix review built from the published rate card lands on figures a buyer can put into a spreadsheet.
The per-transaction side splits by how the card is presented. Card-present transactions start from roughly interchange plus $0.08. Card-not-present and keyed transactions run roughly interchange plus $0.15 to $0.25. Published small-merchant rates land near interchange plus 0.4% and $0.08 in person, and near interchange plus 0.5% and $0.25 online. A flat-rate option also exists at roughly 2.75% plus $0.30 for platforms that want one number instead of a variable one.
How Volume and Ticket Size Shape the Bill
The subscription is fixed, so the effective rate improves as volume grows. A merchant running $10,000 a month pays the same $250 as a merchant running $200,000. Against a flat 2.75% rate, that $10,000 would cost roughly $275 in processing, so interchange-plus stays competitive even at the entry tier. The margin widens as volume climbs, because the markup holds steady while the subscription stays flat.
Average ticket size matters as much as volume. Fixed per-transaction fees make up a larger share of the bill for low-ticket merchants and a smaller share for high-ticket ones. A platform processing 20,000 transactions at $12 each pays more in fixed fees than one processing 2,000 transactions at $120 each, on identical monthly volume. Larger platforms move onto dynamic or custom pricing negotiated against their volume, which is where the published rates give way to terms written for the account.
Registration Changed the Cost Structure
In 2023, Finix registered as a payment processor in its own right and connected directly to Visa, Mastercard, American Express, and Discover as a direct acquirer. That removed a layer of intermediation from its own cost base. Before then, it sat on top of another acquirer, as most payment facilitators of its size still do. The decision to become a payments processor is what makes the low per-transaction fees defensible, since a reseller sitting on top of another acquirer has less room to compress margin.
Capital supports the same position. Finix closed a $75 million Series C in October 2024, led by Acrew Capital with participation from Citi Ventures and Lightspeed, bringing total funding above $208 million. Pricing at this level is easier to sustain with a funded balance sheet than without one.
Underwriting Is a Cost Line Too
Platforms that own payments inherit merchant onboarding. Finix launched automated merchant underwriting in April 2024. The system handles data collection, compliance checks, and risk scoring, returning approvals in seconds. Platforms set their own workflow rules, which decides how many applications route to a human.
That matters to unit economics. Manual review is headcount. A platform onboarding several hundred merchants a quarter is comparing subscription cost against the salary of the people who would otherwise read applications.
Screening That Shows Up in Chargebacks
The risk layer combines machine learning models trained on network transaction data with configurable rule sets. It scores transactions, reads geolocation signals, flags card testing attempts, and profiles email risk. Compliance tooling covers identity document verification, sanctions and watchlist screening, and money laundering review.
Fraud losses and chargeback fees are real costs, and tooling that catches attempts early keeps dispute volume down. Two 2025 releases work on the same margin from a different angle. Account Updater refreshes expired or replaced card credentials, and Network Tokens reduce declines on stored cards. Both recover revenue that would otherwise fail at authorization.
Where Finix Operates and What It Added
Finix runs across the United States and Canada, both markets on the same rate structure. An Interac partnership announced in October 2025 covers Canadian merchants, which matters because Interac debit carries different economics from credit and is the dominant card-present rail north of the border. A WooCommerce plugin released in July 2025 extends the platform to merchants running on that stack without custom integration work.
Neither addition changes the rate card. Both change how much engineering time sits between a platform and its first live transaction, and that time is a real cost that never appears on a processing statement.
The Part of the Bill No Processor Sets
Interchange is the floor under every quote. Networks set those rates, and no processor prices below them. That floor is currently in motion. Visa and Mastercard reached a revised swipe fee settlement with merchants in November 2025 that would lower rates by 0.1 percentage points for five years, ending roughly two decades of antitrust litigation.
An earlier version of that deal was rejected by the court. In March 2024 the networks agreed to limit credit card swipe fees under a $30 billion settlement that a federal judge later declined to approve. Merchant groups have argued for larger reductions in both rounds. Any platform modeling payment margin over a five-year horizon is modeling against a number outside its control.
Performance and Merchant Sentiment
Finix holds a 4.7 rating on Capterra across 42 reviews, with 4.8 for customer service and roughly 95% positive sentiment. Customer service carries the highest score in that set.
Finix reports 99.999% availability and more than 400 million transactions processed daily. Uptime at that level sets what a platform can promise its own merchants.
What the Rate Card Supports
For a platform under $1 million in annual volume with a mid-sized average ticket, $250 per month plus interchange plus $0.08 to $0.25 per transaction generally lands below flat-rate pricing from Stripe Connect or Braintree. Platforms running smaller monthly volumes can take the flat-rate option at roughly 2.75% plus $0.30, which carries no subscription. Above the published tiers, the comparison with Adyen for Platforms or Payrix becomes a negotiation, and each option suits a different mix of volume, geography, and integration depth.
Andrea Bell is a blogger by choice. She loves to discover the world around her. She likes to share her discoveries, experiences and express herself through her blogs. You can find her on Twitter:@IM_AndreaBell
