Introduction to the Taxamo Assure service and the Seller Transaction API.

What is Taxamo Assure by Vertex?

You can use the Taxamo Assure by Vertex service to complete the following tasks:

  • Determine the party (seller, buyer, or Taxamo) who is liable for tax.
  • Calculate the tax rate.
  • Process refunds.
  • Generate invoices.

The service is intended for physical goods valued at €150 or below. For more information, see Taxamo Assure.

For more detailed information about how it works, see How Taxamo Assure Works.

How is it Integrated?

The service is based on the Seller Transaction API. This is a RESTful API that contains a set of endpoints for handling transactions, like sales and refunds.

The API facilitates the integration between Taxamo and your checkout processes. This is shown in the following graphic:

API Simplified OverviewAPI Simplified Overview

API Simplified Overview

If you use Magento, you can use the plugin to integrate Taxamo Assure by Vertex. For more information, see Configuring the Magento Plug-In.

You can also integrate the API directly with your web store. The following table outlines an example of what this integration might look like. It is intended to show how your business processes can be mapped to the endpoints that you send requests to. These examples are simplified to give you a sense of how the API integration works:

Checkout Process Step

Transaction Stage


Buyer places goods in their basket but does not confirm the details yet as they are still shopping.

Order storage

Store Transaction

Buyer confirm a purchase and their payment details are confirmed by your payment service provider.

Order confirmation

Confirm Transaction

You want to issue a refund to your customer, the buyer.

Refund transaction

Refund Transaction

You want to issue invoices to your customers for transactions where Taxamo is liable,


Where Taxamo is liable for VAT, an invoice is generated automatically for confirmed transactions and emailed to the buyer. For more information, see Configuring Invoices.

For a more detailed overview of how the API works, see API Overview.

For more detailed information about how to configure the API, see Configuration Overview.

If you need further help, contact support at

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