Software companies used to build products and leave payments to someone else. A processor would handle the transactions, take the fees, and own the relationship with the merchant. The software company got none of that revenue and had very little say in how the payment flow worked for its users. That arrangement made sense when payments were hard to build and expensive to maintain. It no longer makes sense.

Boards and investors now expect platforms to own their payment flows and earn from every transaction running through their system. SaaS platforms and marketplaces that embed payments into their products can boost average revenue per user by 5 to 10x, according to industry data. The portion of small business merchant acquiring revenue processed through SaaS platforms is expected to grow from 33% in 2024 to 46% by 2029, as businesses move away from traditional processors. Payment facilitation, and the platforms that make it accessible, sits at the center of this.

This article covers 5 PayFac platforms that help software companies monetize payments faster, with a close look at what each one offers, where it fits best, and what to think about when choosing a partner.

Why SaaS Platforms and Marketplaces Are Bringing Payments In-House

Payments generate recurring, transaction-based income that compounds as your user base grows. Platforms can earn through processing markups, premium features like instant payouts, or tailored billing models. That revenue is predictable and scales with usage.

PayFac-as-a-Service providers have compressed onboarding timelines from weeks to days, sometimes hours. Instead of requiring each seller to complete a full merchant account application, automated KYC and AML risk checks run in the background. This reduces drop-off during signup and gets businesses processing revenue faster.

Running payments through a single system also simplifies settlement, reconciliation, and reporting. Accounting teams get a cleaner view of revenue. Leadership gets more accurate forecasting. Manual work goes down, and so do administrative costs and errors.

The 5 PayFac Platforms Worth Knowing

/1. Finix

Finix is a full-stack payment processor that enables businesses to accept and send payments both online and in-store, with direct integrations to American Express, Discover, Mastercard, and Visa. The company processes 432 million transactions daily across the United States and Canada, and its API maintains uptime of 99.999%, which translates to roughly 5 minutes of downtime per year.

What makes Finix a strong fit for growing SaaS companies is its long-term approach to payment ownership. Platforms can start with PayFac-as-a-Service and grow into full PayFac ownership over time, all within the same platform. The APIs, dashboards, and automation tools handle merchant onboarding, risk management, and reconciliation at scale. Finix uses a cost-plus pricing model with full transparency, breaking down every charge and showing the markup so there are no surprises.

In 2025, Finix released features targeting the 22 million businesses without developers on staff. These include Checkout Pages, Payment Links, Payout Links, Tokenization Forms, Virtual Terminals, and Merchant Onboarding Forms. Setup takes minutes. Recurring Billing lets businesses create subscription payments, installment plans, donations, and membership fees through a dashboard with no code required.

Finix also supports a broad set of high-risk industries, including CBD, nutraceuticals, gaming, financial services, and digital wallets, which many other processors avoid. The company has raised $208 million in total funding, with its Series C led by Acrew Capital and co-led by Leap Global and Lightspeed Venture Partners. Revenue quadrupled in the last year. Finix Payouts allows businesses to send money via ACH, real-time payments, Mastercard Send, and Visa Direct through a single API, and the product works as a standalone offering.

/2. Stax Connect

Stax Connect is built specifically for ISVs and SaaS companies looking to integrate payment processing directly into their software. Through a single API, pre-built enrollment, automated settlements, and robust risk management, it lets platforms create a customizable payments flow for their users.

Deployment can happen within 30 days while maintaining PCI compliance. Stax Connect provides dedicated partnership success teams and access to direct interchange rates, enabling platforms to offer favorable pricing to sub-merchants. The platform holds an A+ rating from the BBB.

A Forrester Consulting study commissioned by Stax found that vertical SaaS platforms using Stax Connect can generate an estimated $900K in additional revenue, according to the Total Economic Impact study. One limitation to note is that Stax Connect is currently available only in the United States, which may restrict businesses with international operations.

/3. Tilled

Tilled combines easy-to-integrate payment technology with transparent, tiered pricing. Platforms processing less than $5 million monthly get a 70% revenue share at a $500 monthly fee. Platforms above $5 million monthly get an 80% revenue share at $2,500 per month. Both tiers include customizable merchant onboarding, pricing optimization, terminal management, card-present support, subscriptions, hosted checkout, virtual terminals, and white-label functionality.

Through modern APIs and SDKs, Tilled's system allows software companies to get set up and running in weeks, with no upfront costs or additional headcount. Platforms avoid the regulatory compliance burden and liabilities of becoming a fully registered facilitator. Tilled currently processes payments in the United States and Canada, with expansion into the European Union and the United Kingdom planned.

/4. Worldpay for Platforms

Worldpay for Platforms, formerly Payrix, is built for enterprises with complex hierarchies and global operations. It combines omnichannel acquiring, fraud prevention, and compliance infrastructure under a single umbrella.

The platform offers 3 tiers. Integrated Payments serves as an entry-level revenue option with minimal operational complexity. PayFac-as-a-Service bridges the gap for high-growth SaaS platforms that want payment facilitation while Worldpay handles underwriting and compliance. PayFac Developer is designed for resource-rich companies that want the largest share of payments revenue.

Worldpay processes for 75% of Mastercard PayFacs, which speaks to its scale. The company has been expanding its offering to Canada and the United Kingdom while deepening its presence in Australia.

/5. Rainforest

Rainforest was built from the ground up to support the needs of vertical software platforms. It provides highly customizable, low-code, white-label integration technology with fully embedded payments and reporting.

Merchant onboarding is fully embedded within a platform's product, including application corrections and document uploads. Merchants stay on the platform with no external logins or PDF applications. Rainforest will never contact merchants directly. Its risk model was developed specifically for vertically focused SaaS platforms, and Rainforest works with each platform to align the risk model with the industry and vertical, leveraging custom data to improve transaction monitoring.

The company recently raised an oversubscribed $29 million Series B funding round led by Matrix Partners and Infinity Ventures, after growing revenue by more than 10x. Rainforest has been awarded Venture Atlanta's 2023 Emerging Startup of the Year, The Information's Top 50 Most Promising Startups for 2024, and Global Financial Market Review's Best Payment Technology Innovation USA 2025.

How to Pick the Right PayFac Partner

Integration Timeline and Developer Resources

Building your own payments infrastructure takes months, sometimes years. PayFac-as-a-Service platforms cut that to weeks. Tilled emphasizes API implementation in days. Stax Connect targets 30-day deployment windows. Finix offers both code-heavy and no-code paths depending on your team's capabilities.

Pricing Transparency

Compare revenue-share models, interchange-plus pricing, and cost-plus pricing across providers. Tilled offers 70% to 80% revenue splits. Finix and Stax Connect offer interchange-plus or cost-plus models. Finix specifically removes extra charges for PCI compliance, setup, and fraud protection tools, fees that can add up quickly with other providers and sometimes catch merchants off guard after they commit to a platform.

Compliance and Risk Management

PayFac-as-a-Service platforms handle much of the regulatory compliance and risk management burden, but platforms should confirm exactly what their partner covers versus what remains their responsibility. Rainforest builds vertical-specific underwriting models for each platform. Stax Connect maintains PCI compliance as part of its deployment process.

Payout Flexibility

Finix Payouts lets businesses send money via ACH, real-time payments, Mastercard Send, and Visa Direct through a single API. Rainforest provides merchants a single daily deposit for all payment methods with an itemized deposit report. Both approaches solve different operational needs, so the right choice depends on how your merchants prefer to receive funds.

Scalability

The payment needs of a growing SaaS platform will change as you add subscription tiers, expand geographically, experiment with usage-based billing, or launch marketplace features. Finix's ability to move platforms from PayFac-as-a-Service into full PayFac ownership, all on the same infrastructure, makes it the strongest option for companies planning long-term payment ownership. The infrastructure you build now should be flexible enough to support what comes next, and Finix is built with that progression in mind.