What Is a Payment Gateway? How It Works and What It Costs (2026)

What is a payment gateway?

A payment gateway is the service that takes a customer's card details at checkout, encrypts them, and sends the transaction to the payment processor for approval, then returns "approved" or "declined" to your website or terminal in a couple of seconds. It is the online version of the card reader. As of September 2026, a standalone gateway costs about $25 a month plus about 10 cents per transaction (Authorize.net's Gateway Only plan and PayPal's Payflow Pro are both priced that way), while all-in-one providers such as Stripe and Square include the gateway in their per-sale rate, 2.9% + 30 cents online on Stripe. Whether you pay for a gateway separately depends on one question: do you already have a merchant account?

Sourcing note: gateway and processor prices restate the first-party reads in our merchant services fees guide (Authorize.net, PayPal, Stripe, and Square pricing pages, read September 18, 2026). Providers change rates; confirm on the provider's page before you sign.

How a payment gateway works, step by step

1. Checkout. The customer enters a card on your site, or taps it on a terminal.
2. Encryption. The gateway encrypts the card data so your website never has to store raw card numbers, which is most of what keeps a small business's PCI burden manageable.
3. Routing. The gateway passes the transaction to the processor, which sends it over the card network (Visa, Mastercard, and so on) to the bank that issued the card.
4. Approval. The issuing bank checks funds and fraud signals and approves or declines.
5. Response. The answer travels back through the processor and gateway to your checkout page.
6. Settlement. Later, usually in a daily batch, approved transactions settle and the money moves to your merchant account, then to your bank.

Payment gateway vs merchant account vs payment processor

• Payment gateway: the front door. Captures and encrypts card data and passes it on.
• Payment processor: the router. Moves the transaction between you, the card networks, and the banks.
• Merchant account: where the money lands. A bank account that holds card sales before they are paid out to your business account.

Traditional setups buy these separately: a merchant account from a bank or processor, plus a gateway such as Authorize.net. All-in-one providers such as Stripe, Square, and PayPal bundle all three into one account and one rate, which is why most small businesses never see the word "gateway" on a bill.

How much does a payment gateway cost?

A worked example: 400 online sales a month on a standalone gateway is $25 plus 400 × 10 cents = $65 a month for the gateway alone, before the merchant account's processing fees. On Stripe the gateway cost is inside the 2.9% + 30 cents, so there is no separate $65 line. The standalone gateway only wins when your merchant account's processing rate is low enough to make up the difference; our credit card processing fees guide shows how to compare the two.

Do I need a separate payment gateway?

• No, if you sell through Stripe, Square, PayPal, Shopify, or any all-in-one checkout. The gateway is included and you pay one rate per sale.
• Yes, if you have a traditional merchant account from a bank or processor and want to take payments on your own website. That account needs a gateway such as Authorize.net or Payflow in front of it.
• Maybe, if your volume is high enough that interchange-plus pricing on a merchant account beats a flat rate. Then a $25 gateway is a small line on a smaller total bill.

Choosing between the two biggest all-in-one options? See Stripe vs PayPal for the fee math side by side, and Stripe fees for every line on a Stripe bill.

What to check before you pick one

• Does it work with your website platform? Most e-commerce platforms support a short list of gateways natively.
• Does it keep card data off your servers? Hosted payment pages and tokenization reduce your PCI scope.
• What are the non-sale fees? Batch fees, chargeback fees, and monthly minimums change the real cost.
• How fast do payouts arrive? That is the merchant account's schedule, not the gateway's, but it is the number owners feel.

The bottom line

A payment gateway is the checkout's secure connection to the card networks. If you use Stripe, Square, or PayPal you already have one inside the rate. If you have your own merchant account, budget about $25 a month plus about 10 cents a transaction for the gateway. If your checkout is the real problem, a slow site, a clumsy cart, or payments that do not sync to your books, SuperDupr builds e-commerce platforms with payments wired in from day one.