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Our comprehensive documentation will help you integrate your site with 2Checkout. View integration instructions for Standard, Inline, our API, and webhooks (INS).

Checkout Integration

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Cart Integration

We're integrated with over 100 online carts. Just select your cart from our list, and follow our integration instructions for your cart to get everything set up.

Popular Online Carts

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Knowledge Base

Find all your answers in our Knowledge Base. We provide in-depth articles and how-to's for troubleshooting integration with 2Checkout and your site.

Support Categories

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Try out our developer sandbox to test out our product before signing up. Test integration with our API, webhooks (INS), and other checkout integrations.

Sandbox Details

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Frequently Asked Questions (FAQ)

Can I test all of 2Checkout’s features in the Sandbox?

​Through the Sandbox, you can test:

  • The Payment API
  • The Hosted Checkout solutions
  • All parameter sets
  • INS Messages
  • Recurring and non-recurring billings
  • Fraud responses
  • Coupons
  • Return validation

And almost all of the other features of the 2Checkout integration and payment process, all without needing to apply for a live account! More information about Sandbox testing is located here.

How is a sale created?

The 2Checkout purchase routine works off of a Common Gateway Interface (CGI), so your site will need to contain an HTML form or link with CGI parameters appended that passes the correct parameters (and the customer) to our purchase routine to complete the checkout. Passing in the proper parameters will result in the customer going through the rest of our checkout process (such as entering their credit card information), and after verification, being returned back to your site with a sale confirmation. Please visit the demo site at 2Checkout.com/demo to try out the order process by placing a demo sale.

Carts that Integrate with Inline checkout

Learn how to integrate Inline Checkout with the Developer Documentation.

Carts that currently support Inline Checkout:

Parameter Errors on Checkout Page

If there is a problem with your integration or your account is in a status where it is unable to make live sales, our checkout will give a parameter error (PE-1XX). The parameter error code displayed can range from PE-100 to PE-105 and the buyer will be advised to contact the merchant directly for assistance. The most common causes for a parameter error are as follows:

  • Attempting to place a live sale using a demo account.
  • Attempting to place a live sale while your account is in status P (inactive for live sales)
  • Required parameters are missing or are being passed to our checkout with an invalid value.

If you are receiving a parameter error while placing a live sale please first check your account status on your account homepage to make sure that it is not in status P. Accounts in status P are under review and are temporarily restricted from placing live sales. You will need to contact us directly so that we can assist you with getting the account activated.If your account is not in status P the issue is related to your integration. Please feel free to contact us directly at techsupport@2checkout.com so that we can assist you with troubleshooting the issue.

Instant Notification Service

If your application requires more detailed information throughout the life cycle of the sale, we recommend using our Instant Notification Service (INS). The INS is a service which will notify your application with all the details regarding a specific sale event (such as when an order passes fraud review or a recurring order re-bills successfully).

More information can be found in our Instant Notification Service Documentation.

What parameters can I use?

2Checkout.com supports 2 different parameter sets which when passed into the purchase routine correctly, will create a sale. You may also pass in any additional parameters that you may need and they will be returned to you at the end of the sale. The only restrictions on custom parameters are that they cannot share the name of any parameter that our system uses.

Example usages of each parameter set can be found in our Checkout documentation.

How can I test the 2Checkout.com service?

You may open a free demo account that you can use to test the ordering process by placing demo sales. The 2Checkout.com developer site offers several useful tools that you can utilize to assist you with all aspects of your integration including a purchase machine, return script and Instant Notifications Service simulator.

If you are a shopping cart developer and require a developer account to test your software in a live environment, please contact techsupport@2checkout.com so that we can assist you with this request.

Admin API

Our Admin API provides a way to automate both account and order management processes. This interface provides your application with the ability to pull detailed data from your 2Checkout account and make updates to existing sales, products, coupons and other account details. As an example, your application can make an API call to retrieve detailed sale information and then make an API call to cancel a customer’s recurring billing.

More information and usage examples can be found in our Admin API Documentation.

How do I validate that the message came from 2Checkout?

2Checkout.com provides an MD5 hash to help you verify the authenticity of both the initial passback to your approved URL and all notifications sent by our Instant Notification Service.

More information on validating against the MD5 hash can be found in our Return Process and Instant Notification Service documentation.

The Return Process

When a sale has completed, we can return the customer and the sale parameters to a script or page that you specify. This way you can verify that the sale went through successfully and provide the customer with a confirmation or handle other post order processing.

More information can be found in our Return Process Documentation.

Need help with integration?

Contact our integrations team, techsupport@2checkout.com