GUIDE

How to choose a payment gateway

A gateway decision is harder to reverse than it looks — migrating tokenized card data and re-certifying devices takes real time. Here's the checklist worth working through before signing.

Diagram showing the payment gateway cycle between customer, merchant store, gateway, processor, bank, and merchant account — The basic loop every gateway, including NMI and USAePay, sits inside.

1. Decide whether you need a gateway, a PayFac, or a processor

A gateway like NMI or USAePay routes transactions to acquirers and processors but doesn't hold merchant funds or underwrite risk itself, as the diagram above shows: the gateway sits between the merchant's store and the processor/bank, it doesn't replace either. A payment facilitator (PayFac) such as Stripe or Square acts as the merchant of record and onboards sub-merchants under its own master account. A traditional processor sits underneath both. If you want acquirer flexibility and are prepared to work through an ISO or build partner relationships, a gateway fits; if you want the fastest possible self-serve onboarding and are comfortable with a fixed platform fee, a PayFac may fit better.

2. Check acquirer and processor certifications for your vertical

Not every gateway is certified with every acquirer, and not every acquirer supports every vertical equally well. Ask for the specific, currently-certified list relevant to your industry and geography rather than a total connection count.

3. Understand who sets your price

Gateways sold through partner channels — which includes both NMI and USAePay — typically don't publish one flat rate. Your ISO, ISV, or reseller sets the markup above the platform's buy rate. Ask for the buy rate and the markup separately rather than accepting a single bundled number. Our pricing guide covers this in more depth.

4. Map the integration path

API-level integration gives the most control but the most PCI scope; hosted fields or a hosted payment page shift more of that scope to the gateway; a virtual terminal needs no integration at all but only supports manually keyed transactions. See the integration guide for the trade-offs.

5. Ask about contract length and exit terms

Early termination fees, equipment leases, and auto-renewal clauses are common across the industry and are set by the reseller or ISO, not necessarily the gateway itself. Get the contract term, any early-termination fee, and the renewal notice period in writing before signing.

6. Confirm device and hardware certifications

If you need card-present acceptance, confirm your specific terminal or unattended device model is certified on the gateway you're evaluating — certification lists vary and re-certifying hardware takes time.

This is general background reading, not a recommendation of any specific provider. See our NMI review and USAePay review for platform-specific detail.