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How To: Move to PayPal Complete Payments

This document explains how to migrate to PayPal Complete Payments (the latest PayPal solution) in CS-Cart products. The exact steps and prices depend on multiple factors, such as:

  • Your CS-Cart product, version, and plan
  • When you bought the license, and from whom (CS-Cart or authorized resellers)
  • Any modifications to CS-Cart code that you may have made, etc.

The two general ways are as follows:

  • Ideally, be on (or upgrade to) the latest CS-Cart version and use the built-in PayPal solution. The document will focus on this way.

    Newer CS-Cart versions offer PayPal Complete Payments out of the box, in addition to other improvements and security fixes. Updating CS-Cart also updates all its built-in integrations, including PayPal.

  • Get a PayPal solution for an older CS-Cart version from a third party. This way is not ideal. Prices may vary significantly, and site maintenance becomes more costly in the long run.

    But if your site has a lot of custom code, you’ll need to adapt it for the new CS-Cart version after the upgrade. In some cases, it may be more cost-efficient to purchase (or develop and maintain) a PayPal integration for your older CS-Cart version.

We can help you at any step of the way. We can upgrade your site to the latest CS-Cart version, or refer you to a developer or a ready-made third-party PayPal add-on. For any questions, send us an email to sales@cs-cart.com.

Step 1. Check if you’re already using the latest PayPal solution

For longer than a decade, CS-Cart has offered many PayPal solutions. Some of them got renamed or deprecated over time. You can use names to determine if you’re using the latest solution.

The name of the payment solution is in the settings of your payment methods in CS-Cart, in the Processor field.

  • You are already using a current, up-to-date solution if the name in the Processor field is PayPal Complete Payments or PayPal Complete Payments (Multiparty). It will receive updates with the new versions of CS-Cart.
  • You are using a current solution (but not its latest version) if the name in the Processor field is PayPal Checkout or PayPal Commerce Platform. As you update CS-Cart, the names in the “Processor” field will change automatically to match the current branding.
  • You are using a deprecated solution if the name in the Processor field is PayPal, PayPal Express Checkout, PayPal Pro, PayPal Advanced, PayPal Adaptive Payments, PayPal for Marketplaces.

Note that the above covers only CS-Cart itself, and the addons it comes with by default. The list doesn’t account for any third-party addons or custom PayPal integrations you might have. For example, a third-party developer might offer an addon that also adds a processor named “PayPal Checkout”. If so, updates for that processor don’t come from CS-Cart, but rather from the developer of the addon.

Step 2. Determine your CS-Cart product and version

Here is the best way to determine your CS-Cart product and version:

  1. Sign in to the admin panel of your CS-Cart website. For the purposes of this guide, let’s say that your admin panel is located at https://example.com/admin.php
  2. Once you’re in the admin panel, add ?version to the address bar. Your link should look like this: https://example.com/admin.php?version
  3. Following this link will open a blank page with the information about your product. For example, Multi-Vendor 4.19.1 or CS-Cart 4.18.1

Your next steps depend on what product and version you have.

  • For any product, if your version is 4.18.1 or newer, skip to Step 5. This version is recent enough (at least as of December 2025).

    As the time goes by, it is best to update CS-Cart to even newer versions: 4.19.1 and beyond. This is how CS-Cart’s integration with PayPal Complete Payments receives new functionality and improvements.

  • If your version is older than 4.18.1, it might still include PayPal Complete Payments, but under a different name, and without the latest improvements:

    • For Multi-Vendor (a product for multi-seller marketplaces), you need at least version 4.12.1. It includes PayPal Commerce Platform with multi-party payments.
    • For CS-Cart (a product for single-seller online stores), you need at least version 4.16.1. This version introduces PayPal Checkout for one-buyer-to-one-seller transactions, both in CS-Cart and Multi-Vendor.

    If you are on these versions, you can skip to Step 5. But upgrading CS-Cart to version 4.19.1 and beyond is always recommended, and will be the first recommended step to resolve any issues.

  • If you use Multi-Vendor Cloud, you are always on the latest CS-Cart version available. Skip to Step 5.

Step 3. Check if your CS-Cart license includes updates

CS-Cart offers lifetime and subscription-based licenses. Terms for updates may vary depending on the license and plan you bought, and when you bought it.

  • A lifetime license allows you to use CS-Cart software indefinitely, but usually has a limited number of versions to which you can upgrade.

    For example, you can use any versions released within 1 year from the moment of your purchase. To get access to versions released afterwards, you might need to extend your upgrade period. CS-Cart documentation lists the release dates of all CS-Cart versions.

  • A subscription-based license allows you to use CS-Cart software while your subscription is active. However, it also includes Customer Care (technical support, help with updates, etc.) and access to the latest available CS-Cart versions.

To find your licenses and terms for updates, go to “My Apps → Licenses” in CS-Cart Help Desk. If necessary, prolong the upgrade period to gain access to the latest CS-Cart versions.

If you don’t have a CS-Cart Help Desk account, you may have bought a license from an authorized CS-Cart reseller. If so, contact the reseller you bought the license from, and ask them to transfer the license to you. This will also create your own CS-Cart Help Desk account.

Step 4. Update CS-Cart

CS-Cart documentation has an article on how to install CS-Cart updates.

The upgrade process is incremental. You install updates one by one. For example, when you upgrade from CS-Cart 4.18.3 to 4.19.1, you install two updates: first to version 4.18.4, and only then to version 4.19.1. That’s because some updates may suggest or require extra actions: like switching to a new shipping method integration, or deciding what to do with certain data.

CS-Cart Customer Care specialists can upgrade the site for you. This is a part of any CS-Cart support plan, which comes with a subscription-based license. A lifetime license usually includes a limited period of support, which can be extended. To check your support status, go to “Billing → Support Status” in CS-Cart Help Desk.

Note that Customer Care specialists upgrade only the CS-Cart software and the bundled addons (those available out of the box). They do not adapt any third-party code (including third-party addons and themes) for newer CS-Cart versions. This may require hiring a developer or updating your addons as well. CS-Cart Marketplace for third-party addons and themes shows what is compatible with latest CS-Cart versions.

Step 5. Switch to the current PayPal solution

Once you’re on one of the latest CS-Cart versions, you can start using PayPal Complete Payments. Here is how to proceed:

  1. Set up PayPal Complete Payments for your online store and marketplace.
  2. Test the new payment method on the storefront. Ensure that everything works fine.
  3. Once you’re ready to turn off legacy PayPal solutions, change the status of their associated payment methods in CS-Cart to Disabled.