Authorize.net vs NMI vs Flywire, Which Fits Your Growth Plan

Choosing the right payment gateway isn’t just a technical decision. It’s a strategic one. The gateway you choose affects how fast you can scale into new markets, how many billing workflows you can automate, and how much control your finance team retains.

In this article, we’ll break down three common choices that finance leads in SaaS consider Authorize.net, NMI, and Flywire and where each fits best depending on your goals.

Authorize.net: Trusted and robust

Authorize.net is one of the most recognizable names in the payments world. Backed by Visa, it offers reliability and wide acceptance across industries.

Key benefits

• Simple setup for recurring billing
• Compatibility with most major processors
• PCI DSS compliance built-in
• Supports both ACH and credit cards

Limitations to consider

The tradeoff is flexibility. Authorize.net has fewer customization options and is less developer-friendly compared to other gateways. If you’re trying to build custom payment logic or integrate deeply with a modern SaaS platform, it can feel limiting.

It’s a good fit for businesses with simple billing needs, smaller volume, or those that prioritize stability over extensibility.

NMI: Built for scale, control, and ISV enablement

NMI is designed for businesses that need white-labeling, custom routing, or the ability to control every layer of the transaction stack.

What makes NMI stand out

• Tokenization and multi-gateway routing
• Works well for high-volume SaaS and ISVs
• Enables advanced reporting and reconciliation
• Allows branded checkout and receipt customization

NMI is especially popular among independent software vendors (ISVs) who want to embed payments into their platforms and support multiple payment providers behind the scenes.

When NMI makes sense

However, that control comes with added complexity. Setup requires more technical knowledge, and smaller teams may need development support. If you’re looking for fine-grained control and are ready to invest in configuration, NMI gives you long-term flexibility that pays off.

Pairing NMI with subscription automation tools such as ChargeOver can help mitigate the lift and still give you complete visibility into your revenue workflows.

Flywire: Ideal for global, high-value payments

Flywire is built for cross-border payments and education, healthcare, or enterprise SaaS companies that process large invoices and need to offer local payment methods around the world.

Best suited for global SaaS

• Built-in currency conversion and tax calculation
• Accepts bank transfers and local payment types in 240+ countries
• Optimized for high-value, low-volume payments
• Strong fraud prevention and reconciliation tools

Flywire isn’t just a gateway. It acts more like a payment facilitator, helping you move money across borders without managing all the complexity yourself.

When Flywire is not enough alone

That said, Flywire is not a traditional gateway replacement. If your SaaS company also needs to process U.S. credit cards or support small recurring transactions, you’ll need to pair it with a separate gateway like Authorize.net or NMI.Flywire becomes most powerful when layered into a platform that supports multiple gateways, so you can route global and domestic payments appropriately without manual intervention.

How to future-proof your gateway setup

Most B2B SaaS businesses won’t use just one gateway forever. Your payment infrastructure should evolve as your pricing models, geographies, and customer base evolve.

By integrating with a platform that supports 60+ gateways out of the box, you can start with the right fit for today and keep flexibility for tomorrow. You’ll avoid painful migrations and unlock the ability to route payments intelligently based on customer type, location, or billing cycle.

If your business needs to offer multiple payment methods like credit cards, ACH, SEPA, or digital wallets—all while supporting localized compliance—flexibility at the gateway layer becomes non-negotiable.