How to add a 3rd party payment gateway to your Squarespace site (2022 update)

Why This Matters

You’re ready to take payments online, but right at the finish line, Squarespace yanks the rug out: PayPal, Stripe, and Square, pick one and don't get creative. It sounds simple, unless you’re in a country where Stripe isn’t an option, PayPal quakes in the face of your local regulations, or Square simply isn’t on the map. For countless businesses, this is more than a speed bump. It blocks sales, shrinks your market, and just generally puts a bad taste in your mouth after all your efforts building a beautiful site.

If you’re hoping to serve a global audience, or if you have perfectly legitimate reasons for preferring a niche payment provider, being forced into Squarespace’s payment triad is a straight-up headache. Each awkward workaround costs you time you’d rather spend building the business itself. Meanwhile, you’re left fielding emails from customers unable to pay, or worse, watching abandoned baskets climb. In short, it’s costing you potential orders and actual money, clattering away behind the scenes.

Common Pitfalls

It’s easy to assume that Squarespace, with its slick interface and endless customisability claims, must surely have a way around this. “Maybe there’s a secret menu?” you wonder. Next thing you know, you’re wading through sketchy forum posts or “code injection” tricks that look like a one-way ticket to a support nightmare. Some try and crowbar their favourite gateway into the checkout with javascript or magic wishful thinking, only to break their site or wipe out SEO.

Others invest hours swapping between payment providers, thinking they missed a toggle or a beta feature. No, you didn’t. For better or worse, Squarespace has locked things down at the root: unless your dream processor plays nicely through their own backend, you’re not getting it onto the Core Commerce checkout.

And here’s another classic: paying for a third-party “Squarespace plugin” that promises the earth, only to discover it’s a glorified button generator or perhaps even just a reskinned version of the built-in stuff. Money and time down the drain.

Step-by-Step Fix

Let’s cut through the noise. You can’t add third-party gateways directly to the default Squarespace checkout system. Instead, you need to work around it: bringing in different eCommerce software (think Shopify Lite or SendOwl) to handle payments and then embedding their buy buttons neatly into your Squarespace site. Setting this up is straightforward and gives you true gateway choice. If you set it up properly, checkout feels seamless for your customers. Here's exactly how:

Step 1: Size Up Your Payment Options and Fees

Before diving into signups and buttons, it’s crucial to know where the costs (and savings) are hiding. Not all gateways were created equal, and neither were the platforms sitting in between.

• Shopify Lite (£7/month, at time of writing) can connect to over a hundred gateways, from Adyen to WorldPay. But mind their per-transaction fees: 2.2% + 20p on top of your gateway’s own charges.
• SendOwl (£7-£12/month) brings similar flexibility, but skips the per-transaction fee.
• Both often offer free trials, so make use of those.
• Square, for the record, is only an option if you live in the US. Stripe and PayPal may be unavailable in some countries.

Step 2: Set Up a Shopify (or SendOwl) Account and Connect Your Preferred Payment Gateway

Here’s the trick they don’t tell you: using an external checkout means you’re actually building your products inside another platform, not on Squarespace. Follow these steps:

1. Sign up at Shopify Lite or SendOwl.
2. Dive into the dashboard. In Shopify: click Settings → Payments. In SendOwl: Settings → Payment Gateway.
3. Scroll the list and select your dream provider, whether it's Authorize.net, Klarna, Alipay, or something more obscure. Each has its own onboarding process (proof of business, documents, the usual).
4. Activate the gateway and do a quick test payment if possible.

Step 3: Create a Buy Button for Your Product

Your new eCommerce system isn’t just a backend: it generates buy buttons you’ll use on Squarespace pages. Think of these as tiny, embeddable checkout machines, ready to drop wherever you like.

For Shopify:

1. Go to Products → Add Product. Fill in the title, images, price, and description to match your Squarespace listing.
2. From Sales Channels on the left, click “+” and add “Buy Button.”
3. Hit Buy Button → Create a Buy Button → “Product Buy Button” → select your product.
4. Customise: choose layout (button only, button and image, or full product card). Keep it minimal for best looks.
5. Grab the embed code.

For SendOwl, a similar process: add a product, set price, and hit “generate buy button” to get your code.

Step 4: Embed the Buy Button Code into Squarespace

Now for the handover. The code you copied is pasted into the relevant spot in your Squarespace shop.

1. Navigate to the relevant product page (it’s good practice to match product names and images in Squarespace and your new eCommerce platform).
2. Click Edit → find the spot you want the button (usually in "Additional Info" for product pages, or in a regular section for more general buy links).
3. Insert a Code Block.
4. Paste your Shopify or SendOwl Buy Button code.
5. Save and check that the live page displays the button correctly, styled to fit your site.

Step 5: (Optional) Hide Squarespace’s Native Buy Buttons and Cart

To avoid confusion for your customers (are they paying through Button A or Button B?), you might want to strip out Squarespace’s original “Add to Cart,” quantity selectors, and any variant dropdowns. This makes your embedded checkout the star of the show.

Add this snippet to your site’s CSS (Design → Custom CSS):

/* Hide Squarespace e-commerce buttons and variants */
.product-variants,
.product-quantity-input,
.sqs-add-to-cart-button-wrapper {
  display: none !important;
}

This will make the native Squarespace buying options invisible for all products on your site.

Step 6: Test, Tweak and Communicate

Once the button is live, place a test order. Make sure the money lands in your gateway, and that all notifications (confirmation emails, receipts) go to the right addresses.

On the site, update product descriptions or banners to briefly flag the change: “Payments securely handled via [Your Provider],” with a link to their trust badges if available. Shoppers like transparency, especially when checkout looks a little different than usual.

What Most People Miss

It’s tempting to treat this as a pure technical project. However, switching checkout flows carries subtle risks and opportunities. Make sure your refund/returns terms, emails, and customer support are harmonised across both Squarespace and your new payment platform. The last thing you want is refund requests wandering off into the ether because two systems aren’t talking.

Also, pay attention to reporting. With two eCommerce systems in play, you’ll need a new habit for accounting and analytics, keeping tabs on both platforms to track VAT, inventory, and sales figures. Some users skip this admin step and regret it at tax time.

Remember to monitor your gateway even after setup. Payment processors might change their terms, introduce new fees, or update their security checks, especially for workarounds like this. Stay alert to emails from providers and check in with the Pixelhaze community for updates.

The Bigger Picture

Opening up new payment gateways goes beyond technical tweaks. It lets your business reach a wider audience. If you want to go international, accept obscure currencies, or target markets underserved by PayPal or Stripe, you have that flexibility now.

If Squarespace’s native commerce holds you back as your shop grows, this approach puts you halfway toward a future-proof setup. Feeling boxed in by Squarespace? Move more products onto Shopify or SendOwl. Or, when you’re ready, move the entire shop there, leaving Squarespace for bold, beautiful content and landing pages.

This saves you hours dealing with declined cards, sorting through payment errors, or fixing messy “manual invoice” workarounds. Now you have a system that works for you.

Wrap-Up

In short: while Squarespace’s checkout is locked to a limited trio, you can work around this by embedding Shopify or SendOwl Buy Buttons. This lets you offer almost any payment gateway on your Squarespace store. A few minutes up front means fewer headaches (and lost sales) down the line.

Don’t forget: always test thoroughly, keep your messaging clear, and routinely compare fees so you’re not caught by surprise changes.

Want more helpful systems like this? Join Pixelhaze Academy for free at https://www.pixelhaze.academy/membership.

FAQ

Can I add Klarna/Alipay/other non-Squarespace gateways to my store?
Yes, if you use external eCommerce platforms like Shopify Lite or SendOwl and add buy-button embeds as above.

Are there extra costs?
Usually yes: expect a monthly fee for your external eCommerce platform, and possibly extra transaction fees on top of the payment processor’s own cuts.

Can I keep Squarespace’s built-in checkout live at the same time?
You can, but it’s usually best (for clarity and admin sanity) to pick one checkout flow per product or page.

Will this mess up my analytics or inventory?
You’ll need to track sales through both Squarespace and your new payment platform, as they don’t share inventory or stats automatically.

Jargon Buster

• Payment gateway: A service that processes card transactions securely on your behalf.
• Buy Button: A snazzy piece of code or widget that allows customers to purchase directly from your web page.
• eCommerce platform: Software that handles product listings, payment, and order fulfilment.
• Transaction fee: A small % or fixed fee taken from each purchase by payment processors and/or eCommerce platforms.
• Code Block: A Squarespace element where you can paste external HTML or scripts.

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