Almost any example of payment gateway software you can name is a checkout box you have already typed a card into. The names behind those boxes are a short list, and the useful way to read it is not by features. It is by whether the gateway comes bolted to a merchant account or can be pointed at any bank you like.
Example of payment gateway names, and what each one really is
Stripe. A gateway with an aggregated merchant account attached, sold as one product. Signup is fast because the account already exists and you join it. Stripe publishes its own policies on which businesses it will and will not process for, including its position on MATCH-listed merchants, and those policies are the real terms of the relationship.
Square. Same shape as Stripe from a merchant’s point of view, weighted toward in-person selling and its own hardware. The gateway function and the account are again the same company.
PayPal. Several products under one name. A wallet button, an aggregated processing account, and a separate gateway product that can front other processors. Which one you signed up for changes what happens when a payment is disputed, and it is worth checking rather than assuming.
Braintree. A PayPal company, positioned for developers, with a gateway that supports card, wallet and alternative payment methods.
Authorize.net. One of the oldest gateways still in wide use, now owned by Visa. This is the classic independent model: the gateway is a component and the merchant account behind it is a separate relationship, so the same checkout can survive a change of bank.
NMI. A gateway sold largely through processors and resellers rather than direct, built to route to many acquirers. You often meet it as the technology under somebody else’s brand.
The only distinction that matters on a bad day
Read that list again and it sorts into two piles. Stripe, Square and PayPal bundle the gateway with the account. Authorize.net and NMI are gateways you attach to an account of your own. Braintree sits closer to the first pile.
Bundled means fast and simple until the account is reviewed. Because the same company owns both halves, a closure takes the checkout with it. Unbundled means slower to set up and more moving parts, and it means a bank change is a settings change rather than a rebuild. That is the whole argument, and it is spelled out further in the aggregator versus merchant account comparison.
What none of these examples tell you about your rate
A gateway fee is a small, visible line. It is not your cost of accepting cards. The bulk of that is interchange set by the card networks, plus the acquirer’s markup, plus assessment fees, and none of it is decided by which gateway you picked.
So comparing gateways on their monthly fee is comparing the wrong number. Compare the schedule from the party holding your merchant account, in writing, and make sure reserve terms appear in the same document. How high risk pricing and reserves work explains what should be on that page.
Which examples will not board a hard-to-place business
The bundled products publish prohibited business lists, and those lists are enforced by automation rather than negotiated by a salesperson. If your category appears, no integration choice fixes that, and an approval that slips through is a countdown rather than a win.
The unbundled gateways have no view on your category at all. They are technology. The opinion lives with the acquiring bank you connect them to, which is why a business in a flagged category usually ends up on an independent gateway with a specialist acquirer behind it. That combination is what a high risk payment gateway actually refers to, and it pairs with dedicated high risk processing rather than replacing it.
How to pick from a list like this
Start from the account, not the gateway. Find out who will underwrite your business as it really operates, then ask which gateways that acquirer supports. The shortlist gets very short very fast, and it will be the right shortlist.
If you have already been closed somewhere, do that in the other order at your peril. Rebuilding a checkout around a gateway your next acquirer cannot use is a week you do not get back. The sequence after a closure is in what to do when your processor drops you.
Frequently asked questions
Is Shopify Payments a gateway? It is a bundled payments product inside a store platform, so from a merchant view it behaves like the first pile: the gateway and the account arrive together. Shopify also publishes a list of third-party providers you can connect instead, and that list is worth reading before you commit a store to one route.
Are older gateways worse than newer ones? Not for what a gateway does. Authorize.net predates most of the market and still moves transactions reliably. Newer products tend to have nicer developer tooling. Neither difference affects whether a bank approves you.
Can I use a gateway without a merchant account? Only by using one that includes an aggregated account. A standalone gateway has nothing to settle into on its own, which is the practical meaning of the unbundled model.
Does the gateway I choose change my approval odds? Only through compatibility. Underwriting reads your business, not your integration. But choosing a gateway your intended acquirer cannot connect to will absolutely stop the deal, so ask before you build.