Many merchants inherit a gateway from their first processor without evaluating whether it's the right fit. Gateway lock-in can complicate future processor switches, limit access to features like recurring billing and Level 2/3 data, and in some cases expand your PCI compliance scope unnecessarily. The gateway decision deserves the same attention as the processor decision.
What a payment gateway actually does
A gateway is the technology layer that sits between your checkout and your payment processor. When a customer enters card details, the gateway encrypts that data, routes the authorization request to the processor, receives the response, and returns an approval or decline to your checkout in seconds. It handles the transport and security of the transaction; the processor handles the banking relationship and settlement.
That distinction matters because the gateway and processor can be separate vendors. Many merchants use one gateway across multiple processors, which is why gateway selection affects processor flexibility. A gateway tied exclusively to one processor locks you in. A gateway that supports multiple processors gives you the ability to switch processors or add a backup account without rebuilding your checkout.
What gateway selection actually determines
PCI scope
How cardholder data flows through your system determines your PCI compliance burden. A gateway with hosted payment fields or an iFrame keeps card data off your servers entirely, reducing your PCI scope to SAQ A. Direct API integrations that handle raw card data require SAQ D compliance; significantly more work and cost.
Feature availability
Recurring billing, Level 2 and Level 3 data, customer vaulting, partial authorizations, and surcharging capabilities vary significantly across gateways. A gateway that doesn't support the features your business model requires forces workarounds or a rebuild later.
Processor flexibility
Gateways that support multiple processor integrations give you the ability to switch processors or add a redundant account without touching your checkout code. Proprietary gateways tied to one processor mean a processor switch requires a gateway migration as well.
Platform integrations
Shopify, WooCommerce, Salesforce, HubSpot, and most major ecommerce and CRM platforms have native gateway integrations for a short list of providers. Choosing a gateway your platform supports natively avoids custom development and reduces ongoing maintenance.
Redundancy and failover
A single gateway with no failover means gateway downtime becomes revenue downtime. Multi-processor gateways can route transactions to a backup processor if the primary is unavailable. For merchants with meaningful daily volume, this is worth designing for explicitly.
Gateway cost
Gateway fees vary from $0 (bundled with processor) to $25 or more per month plus per-transaction fees. For merchants processing multiple payment methods or using advanced features, gateway cost can be a meaningful line item. We review whether what you're paying is competitive.
Why Cambridge uses NMI for many of our clients: NMI (Network Merchants, Inc.) is a payment gateway that supports connections to hundreds of processors, meaning your gateway relationship stays intact when your processor changes. It offers a robust feature set including recurring billing, customer vaulting, Level 2/3 data, ACH, and surcharging. For merchants who want flexibility to move between processors without a checkout rebuild; or who want to add a redundant processor later; NMI provides that foundation. It's also the gateway behind our own merchant portal, which clients can access directly. Not every merchant needs NMI; but for those who do, it's the right tool.
“We had issues working with Stripe and Squareup, so we moved to Authorize.net and it was a very outdated and confusing system to work with; especially with our recurring payments. Then a friend recommended Cambridge and they made everything so easy to understand. Anytime I've had issues or concerns, I had the support I needed to find and decide on the best solution. CambridgeCommerce helped us set up an easy to use system which can be adapted whenever challenges arise. They allow me to stop worrying about the complex world of payment processing and focus on growing my business.”Health and wellness subscription business Gateway migration from three prior platforms; one stable setup
Common gateway problems we solve
- Gateway locked to a processor the merchant wants to leave; forcing a simultaneous processor and gateway migration
- Gateway doesn't support recurring billing features needed for a subscription launch
- Card data flowing through merchant servers due to a direct API integration; expanding PCI scope unexpectedly
- No failover path when the primary gateway or processor has an outage
- Gateway fees that haven't been reviewed against current market pricing in years
- Platform integration gapsrequiring custom development for a gateway that has a native connector elsewhere