PrestaShop

Kustom Checkout for PrestaShop is an embedded checkout module that keeps the customer in your store rather than redirecting them out. It’s built and supported by Invertus, and published on the PrestaShop Addons marketplace as Kustom Checkout (official). This page covers installing it, configuring credentials and environment, mapping order statuses and running captures and refunds from the back office.

Before you start

• PrestaShop 1.7.2.x up to 9.
• PHP 7.1.x or newer. The upstream module notes contradict themselves here — they cap PHP at “latest compatible with PrestaShop 8” while claiming support up to PrestaShop 9. Use the PHP version your PrestaShop release certifies and confirm with Invertus if you’re on 9.
• Prices configured to two decimal places. The module requires it, and one decimal produces totals Kustom rejects.
• A Kustom merchant account with API credentials — see Activate Kustom Checkout on your platform. Generate them for the environment you’re configuring: the playground Portal for sandbox, the live Portal for production.

If your store runs the old Klarna Checkout module, that module is no longer maintained and now redirects to the Kustom Checkout product page. Install Kustom Checkout, verify your credentials and settings, deactivate the previous Klarna Checkout module and test in a development environment before deploying to production. Don’t run both.

Step by step

1. Install the module

Either route works.

From the Module Manager. Log in to the back office, go to Modules → Modules Manager, click Upload a Module and drop in kustomcheckoutofficial.zip. You can also search for “Kustom Checkout” in the Module Manager and install it directly from the marketplace listing.

Over FTP. Download and extract kustomcheckoutofficial, upload the folder to /modules, then in the back office go to Modules → Modules Catalog, search for Kustom and click Install.

The marketplace listing is Kustom Checkout on PrestaShop Addons.

To reach the settings later: Modules → Module Manager, search Kustom, click Configure.

2. Select the environment and enter credentials

The module has two checkboxes for Sandbox and Production. Production is selected by default, so switch to Sandbox before you test.

Enter the API Username and Password generated in the Portal for the environment you selected. Sandbox credentials in production mode won’t work, and the failure is quiet.

Enable Debug Mode while you’re testing to get full logs. Turn it off afterwards.

3. Map Kustom order states onto PrestaShop statuses

The module ships these defaults. Change them to match how your fulfillment team reads the order list.

Kustom state	Default PrestaShop status
New orders	Payment accepted
Captured orders	Shipped
Cancelled orders	Canceled
Refunded orders	Refunded
Partially captured orders	Partially captured

4. Decide how captures happen

Automatically. Enable Capture upon fulfillment, choose the order status that should trigger it — typically Shipped — and save. Moving an order into that status captures the payment.

Manually. Go to Orders → Orders, open a Kustom order and click Capture Payment or Cancel Order.

5. Optional settings

• Allow automatic order status change. Enabled, a Kustom status change updates the PrestaShop order. Disabled, only the initial status is ever applied.
• Styling. The checkout’s appearance can be customized if your Kustom account supports it.

6. Go live

Switch the environment to Production, replace the credentials with the ones from the live Portal, disable debug mode and run one real purchase.

Check that it works

In Sandbox:

1. Add a product to the cart and go through checkout. The Kustom checkout should render embedded, not as a redirect.
2. Complete a payment with test data.
3. Confirm the order appears under Orders → Orders with the status you mapped to “New orders”, and that the total matches.
4. Capture it — automatically by moving it into the trigger status, or manually from the order — and confirm the status moves to your “Captured orders” mapping.
5. Refund it from the Manage Kustom Order section and confirm the status follows.
6. Open the module’s logs and confirm each call shows a request, a response, its context and a correlation ID. Keep the correlation ID: it’s what support will ask for.

Then repeat once in production with a low-priced real purchase.

Variations

Partial captures and partial refunds

Both are supported from the back office, unlike on several other platforms.

• Partial capture — click Capture Order and select the individual items, or an amount.
• Partial refund — the same flow from the Manage Kustom Order section. The refund button only appears after a capture, because there’s nothing to refund before then.

Troubleshooting

The checkout doesn’t render. Check the environment checkbox against the credentials you entered — the default is Production, which is the wrong pairing for a sandbox key.

Totals don’t match. Set price display to two decimal places.

A status never changes. Check Allow automatic order status change. With it disabled, only the initial status is ever applied and everything afterwards has to be done by hand.

For module and technical questions, contact Invertus at support@invertus.eu. For account, payout or specific-purchase questions, contact support@kustom.co.

Related

• Capture an order — what capture means on Kustom’s side
• Refunds — including the production test purchase you just made
• Open source platform responsibility — what you own running Kustom on PrestaShop
• Activate Kustom Checkout on your platform — getting the merchant account and credentials
• Authentication and environments — sandbox versus production credentials
• Test data — identities and cards that pass in sandbox
• Order management — the states the status mapping is mapping
• Platform catalogue — the other platforms with plugins