Custom payment gateway

Shopify custom payment gateway: the three routes that actually exist.

You have a gateway that approved you, and Shopify will not show it in Settings. Community threads say "build a custom app", developers quote months, and Shopify's own docs point at a programme you cannot apply to as a merchant. Here is what is genuinely possible, who each route is for, and the one you can switch on in 24 to 48 hours.

See pricing → How it works →

Why you cannot just add a gateway to Shopify

Shopify's checkout is closed. Card entry, tokenisation and the call to the processor all happen inside Shopify's hosted checkout, and only gateways that Shopify has integrated and enabled for your country appear in Settings. A merchant's custom app can read carts and write orders, but it cannot redirect the payment step to an outside gateway. That is by design: Shopify guarantees the card form, so it controls who sits behind it.

Two things get confused with a custom gateway and are not one:

Manual payment methods. "Custom payment method" in Settings is bank transfer, cash on delivery or money order. Orders arrive as pending, no card is captured.
Buy Button or Storefront API carts. These still hand off to Shopify's checkout for payment.

Route 1: a Shopify Payments App, built by the provider

Shopify's payments app framework lets a payment provider build an integration that appears in the gateway list. The provider, not the merchant, applies to Shopify's partner programme, passes a compliance and security review, and builds against the Payments Apps API. Timelines run months, and Shopify decides who is admitted. If your gateway is not on the list, the fix is theirs to build, and many small acquirers never will. Ask your provider; if they say "we are working on it", plan as if they are not.

Route 2: offsite or hosted payment on Shopify Plus

Plus merchants can use providers that redirect the buyer to a hosted payment page and return them after capture. That still requires the provider to have a Shopify payments app of the offsite type. Plus gives you more checkout control through Checkout Extensibility and Functions, but it does not let you paste an API key from an arbitrary gateway. Route 2 is Route 1 with more plan cost.

Route 3: your own checkout, connected to any gateway

Move the checkout step off Shopify's hosted checkout and onto a subdomain of your brand, such as checkout.your-brand.com. Buyers browse and add to cart on your Shopify storefront as before. When they press Buy, they pay on your checkout page, which talks to your gateway's API directly. After capture, the paid order is written back into Shopify with line items, buyer, address, shipping and discount code, tagged [cascade].

This is what CascadeCheckout does. It works with any gateway that has an API: NMI, Nuvei, Airwallex, Checkout.com, PXP, Adyen, Whop, a bank's direct gateway, an acquirer in your region, a crypto rail, or a custom HTTP endpoint. It does not need Plus, a payments app, or a change to your theme beyond one small snippet. And because the checkout is ours to route, you can wire two or more gateways and let the cascade retry the next one on a decline. See the flow step by step.

Send keys

API credentials for each gateway that approved you. Sandbox first, then live.

We wire the checkout

Subdomain, TLS, PCI-tokenised card form, 3DS, webhooks, refunds, order write-back.

Test and go

One live order per route. Confirm it lands in Shopify. Switch the Buy buttons.

Comparing the three

	Payments App	Plus offsite	Own-domain checkout
Who builds it	The gateway	The gateway	CascadeCheckout
Plan required	Any, if the app exists	Shopify Plus	Any
Time	Months, if ever	Months, if ever	24-48 hours after keys
Gateways supported	Only integrated ones	Only integrated ones	Any with an API
Multiple gateways with failover	No	No	Yes
Shop Pay	Depends	Depends	No
Orders in Shopify	Native	Native	Written back via Admin API

What a real gateway integration has to cover

Whoever builds it, a custom gateway connection is more than "send card, get approval". Ask how each of these is handled before you trust a quote:

Card tokenisation so raw card data never touches your server (SAQ A scope).
3-D Secure, including the redirect leg and the result codes that decide retry versus decline.
Webhooks or polling for asynchronous outcomes, captures, refunds and chargebacks.
Idempotency so a retried request cannot charge twice.
Refunds and partial refunds from the store's admin, not a separate dashboard.
Currency handling that matches the Shopify order to what the buyer was charged.
Descriptor control, so the statement reads as your brand.

Frequent questions

Can I add my own payment gateway to Shopify?

Not through Settings unless Shopify has integrated that gateway for your country. You can connect any gateway with an API by running the checkout step on your own domain and writing orders back into Shopify.

Does a custom payment gateway need Shopify Plus?

Offsite and hosted payment apps require Plus, and the provider still has to have built a Shopify payments app. An own-domain checkout works on every plan.

Will orders still show in Shopify?

Yes. CascadeCheckout writes each paid order into Shopify with full detail so fulfilment, apps and reporting continue as normal.

What is the 'custom payment method' in Shopify Settings?

A manual method such as bank transfer or cash on delivery. It records the order as pending and captures no card. It is not a gateway.

Bring your store URL and the gateway that already said yes.

Live in 24-48 hours. Founder-answered support on WhatsApp.

See pricing →

Third-party gateways Shopify lists → · Own-domain checkout → · NMI on Shopify → · Supported gateways →

CascadeCheckout is checkout software, not a payment service provider, bank or merchant-account seller. You contract with your own gateway or acquirer, disclose your real business category to them, and receive payouts from them. We never hold funds and we do not promise that any processor will approve you.