How can I switch my SaaS platform from flat-rate payment pricing to interchange-plus without rebuilding my integration?

You can switch your SaaS platform from flat-rate payment pricing to interchange-plus without rebuilding your integration by working with an embedded payments partner like Fiska that can support pricing changes, merchant-level configuration, reporting, and onboarding without forcing you to rebuild your core payment flows.

For most SaaS platforms, the hardest part of moving to interchange-plus is not the checkout screen or the payment API. It is the commercial and operational layer behind the integration.

That includes:

• How merchants are priced
• How fees are passed through
• How your margin is calculated
• How reporting and reconciliation work
• How merchants understand their processing costs
• How your platform earns revenue from payments

This is why switching to interchange-plus should not be treated as a purely technical migration. It is a payment strategy decision.

Why SaaS platforms move away from flat-rate pricing

Flat-rate pricing is simple. A merchant pays one blended rate, such as a fixed percentage plus a transaction fee, regardless of the underlying cost of the card.

That simplicity is useful early on. But as a SaaS platform grows, flat-rate pricing can become limiting.

Flat-rate pricing can make it harder to:

• Understand true payment costs
• Build transparent merchant pricing
• Optimize margins by merchant segment
• Offer competitive rates to larger customers
• Monetize payments as a serious revenue stream
• See which transaction types are profitable or unprofitable

Interchange-plus pricing gives platforms and merchants more visibility. Instead of hiding costs inside one blended rate, it separates the underlying card network costs from the platform or processor markup.

For SaaS platforms, this can create a more flexible and profitable payment model.

You do not always need to rebuild your integration to switch from flat rate to interchange-plus

Switching from flat-rate pricing to interchange-plus does not always require a full payment rebuild.

If your existing payments provider already supports both fixed-rate and interchange-plus pricing, the change may mostly happen at the pricing, reporting, and reconciliation layer.

In that case, your checkout flow, payment acceptance logic, tokenization, and merchant-facing experience may stay largely the same.

What changes is how payments are priced, reported, and monetized.

That usually means:

• Configuring new merchant pricing
• Updating fee reporting
• Adjusting reconciliation workflows
• Deciding which merchants stay on fixed-rate pricing
• Deciding which merchants move to interchange-plus
• Reviewing how your platform earns margin from payments

But not every provider gives you that flexibility.

If your provider dictates the pricing model, controls the merchant relationship, or only gives you limited visibility into costs and margins, switching pricing models may require a bigger change.

For example, if you are using a provider with a standard fixed-rate model, such as Stripe, you may need to move to an omnichannel payments partner that gives you more control over pricing.

How Fiska helps SaaS platforms set the right pricing model

Fiska helps SaaS platforms integrate omnichannel payments without locking them into a single pricing model.

Our cost base is interchange, which gives platforms more room to build a profitable payments model while staying competitive with merchants. From there, you decide how to price payments.

You can offer:

• Fixed-rate pricing for smaller merchants that value simplicity
• Interchange-plus pricing for larger or more price-sensitive merchants
• Different pricing by merchant, segment, volume, or vertical
• Payments as a standalone revenue stream or bundled into your SaaS pricing

The key point is that Fiska doesn’t dictate your pricing.

As Patrick Hunyh, CEO of Fiska said, “Because of the revenue share structure, our interests are extremely aligned. We want them to qualify for the lowest interchanges possible. We want them to set final pricing as high as possible… Because we’re only making money when they’re making money.”

We give you the infrastructure, cost visibility, and support to choose the model that makes sense for your platform.

That includes:

• A true revenue share, splitting 50% of the profit above interchange
• Online and in-person payments through one API
• Pre-certified terminal connectivity
• Embedded merchant onboarding
• U.S. and Canada coverage
• Interchange-based cost visibility
• Flexible merchant-level pricing
• Reporting and reconciliation tools
• Support with payment strategy, pricing, and rollout

This means you can move beyond one-size-fits-all payment pricing.

For example, you might start most merchants on a simple fixed rate because it is easier to sell and understand. But for larger merchants, where pricing matters more, you can offer an interchange-plus model that reflects their volume and cost profile.

Fiska gives you the flexibility to do both.

Instead of rebuilding your payments stack or becoming a payment facilitator yourself, you can integrate once, offer omnichannel payments, and choose the pricing strategy that best supports your software business.

To get started with Fiska, book a no-obligation call with our team

Frequently asked questions (FAQ): Switching from flat-rate to interchange-plus pricing without a new integration 

Can a SaaS platform switch from flat-rate pricing to interchange-plus without rebuilding its payment integration?

Yes. In many cases, the main changes are commercial, operational, and reporting-related rather than a full technical rebuild. With the right embedded payments partner, a SaaS platform can move toward interchange-plus pricing while keeping the core payment experience largely intact.

Why would a SaaS platform move from flat-rate to interchange-plus?

A SaaS platform may move to interchange-plus to gain more pricing transparency, improve margins, offer custom merchant rates, and build payments into a more scalable revenue stream.

Does Fiska support custom merchant pricing?

Yes. Fiska supports flexible pricing configuration per merchant, allowing SaaS platforms to tailor rates by merchant, vertical, customer segment, or volume.

Is interchange-plus always better than flat-rate pricing?

Not always. Flat-rate pricing is simpler and can work well for smaller platforms or merchants that value predictability. Interchange-plus is often better for platforms that process higher volume, need more pricing control, or want better visibility into payment economics.

What is the biggest operational change when moving to interchange-plus?

The biggest change is usually reporting and reconciliation. Interchange-plus creates more detailed fee visibility, so SaaS platforms need clear reporting around interchange, network fees, markup, margin, and merchant-level effective rates.