Every vertical SaaS platform sits on top of payment volume. Your merchants process transactions through or alongside your software — scheduling, invoicing, point of sale, e-commerce, field service. That volume is raw material. The question is whether you're capturing any of its value.
Most platforms know payments is a revenue opportunity. Fewer can explain how the money actually flows. This article breaks down the four models, the economics of each, and the thresholds where each one starts to make sense.
Model 1: ISV Referral
The simplest path. You partner with a payment processor, embed their acceptance tools in your product, and earn a residual on merchant volume. The processor handles everything — underwriting, compliance, settlement, support.
Your revenue: 5 to 25 basis points on gross merchant volume. On a platform with 200 merchants processing $150K each ($30M annual volume), that's $15K to $75K per year. It's low-touch, low-risk, and you can be live in weeks.
The ceiling is real. You don't control merchant pricing, you don't own the processing relationship, and your share of the margin is typically 15–25% of the total payment economics. But for platforms under $50M in volume, the simplicity is worth it.
Model 2: Gateway / Enhanced Residuals
A step up from basic referral. You partner with a gateway provider or negotiate enhanced terms with a processor that give you a larger share of the payment margin. You may take on some merchant-facing responsibilities — boarding, first-line support — in exchange for improved economics.
Your revenue: 15 to 40 basis points net. On the same $30M in volume, that's $45K to $120K per year. Implementation is more involved ($25K–$75K), and you'll need at least one person who understands the payment flow. But the economics are 2–3x better than basic referral.
This model works well for platforms in the $20M to $75M volume range that want better economics without the full operational weight of payment facilitation.
Model 3: PayFac Lite / Managed PayFac
You become a sub-merchant aggregator under a registered payment facilitator. You own merchant onboarding, set merchant pricing, and keep the spread between what you charge and what you pay the processor at wholesale (interchange plus a small markup).
Your revenue: 30 to 90+ basis points net. On $30M in volume, that's $90K to $270K. On $100M, it's $300K to $900K. The economics are 4–5x better than referral at scale.
You take on merchant underwriting (within parameters), compliance monitoring, chargeback first-response, and settlement management. Implementation costs $50K to $200K, and you need operational capacity — either internal or through a managed service provider.
This is the model that changes payments from a feature into a business line. Most platforms that reach $50M+ in volume and have the operational maturity to support it should be evaluating this transition.
Model 4: Full Payment Facilitation (Direct PayFac)
You register directly with Visa and Mastercard as a Payment Facilitator. You own the full stack: underwriting, compliance, settlement, dispute management, network reporting. You buy processing at the lowest possible rate and keep maximum margin.
Your revenue: 50 to 100+ basis points net. The economics are the best available. But the cost to get here is significant: $500K to $2M+ in implementation, 12–18 months to launch, dedicated compliance and risk staff, and ongoing regulatory obligations.
This model only makes sense at $100M+ in annual volume. Most platforms that pursue full PayFac too early delay revenue by 12–18 months and burn capital that should go into the core product. It's the end state, not the starting point.
The Revenue Curve Is Not Linear
The economics of each model look like steps, not a slope. You don't gradually earn more by processing more volume under the same model. You earn meaningfully more by moving to the next model when your volume justifies it.
This is why the most important discipline in payments monetization is re-evaluating annually. The platform that was right to start in ISV Referral at $15M in volume is leaving $100K+ on the table by staying there at $60M.
The Costs Everyone Forgets
Revenue is only half the equation. Each model carries operating costs that don't appear in the vendor pitch deck:
- Merchant support: you're now first-line for payment questions. Budget 0.5 to 1.5 FTEs depending on merchant count.
- Compliance: $5K to $25K annually for PCI compliance, depending on your model and volume.
- Integration maintenance: 10–20% of your initial build cost annually. Payment APIs change, card network rules update, and edge cases surface.
- Chargeback management: in PayFac models, you carry first-response responsibility and potentially reserve exposure.
Smart operators focus on operating costs first because those determine long-run economics. Implementation costs are one-time. Operating costs are forever.
Where to Start
If you're not monetizing payments today, start by quantifying the opportunity. Take your merchant count, multiply by average monthly volume, and model the revenue under each approach.
The gap between what most platforms earn on payments and what they could earn is usually the most surprising number in any strategy conversation.
The Margin Multiplier does this calculation in about 60 seconds. It won't tell you which model to choose, but it will show you the size of the opportunity you're either capturing or leaving on the table.