How do I track Ecommerce interactions using the Tag Manager data layer?

When implementing Matomo Ecommerce tracking on a website with the most flexibility, it can be recommended to leverage the Tag Manager data layer. This works in a similar way to Google Tag Manager (GTM).

Here are the steps to follow to implement Ecommerce Tracking using the data layer:

Step 1: Create a “Data-Layer” variable eg named PurchaseInfo whose “data layer variable name” is ecommerce.purchase.

Step 2: Create a “Custom Event” trigger which triggers when the Event Name is purchase.

Step 3: Create a Custom HTML tag that fires on this “Custom Event” trigger to track your Ecommerce interaction. For example to track an Ecommerce order you would write:

<script>
window._paq = window._paq || [];
var purchaseInfo = {{PurchaseInfo}};
//console.log(purchaseInfo);
window._paq.push(['trackEcommerceOrder',
  purchaseInfo.id, // (required) Unique Order ID
  purchaseInfo.revenue, // (required) Order Revenue grand total (includes tax, shipping, and subtracted discount)
  purchaseInfo.orderSubTotal, // (optional) Order sub total (excludes shipping)
  (purchaseInfo.tax || 0), // (optional) Tax amount
  (purchaseInfo.shipping || 0), // (optional) Shipping amount
  (purchaseInfo.discount || false) // (optional) Discount offered (set to false for unspecified parameter)
]);
</script>

Step 4: Finally, within your ecommerce backend website/app itself (not within the tag manager), trigger the tag manager event like this in JavaScript:

window._mtm = window._mtm || [];
window._mtm.push({
'event': 'purchase',
'ecommerce': {
  'purchase': {
    'id': 'dynamic value',
    'revenue': 'dynamic value',
    'orderSubTotal': 'dynamic value',
    'tax': 'dynamic value',
    'shipping': 'dynamic value',
    'discount': 'dynamic value',
    }
  }
});

and replace dynamic value with the actual value for this commerce interaction. This tag manager event purchase will then trigger the custom HTML tag which will in turn, track the Ecommerce interaction in Matomo, using your Data layer’s dynamic variables.

Please note that if you are using the Matomo Tag Manager within Matomo for WordPress and you are wanting to track WooCommerce, Easy Digital Downloads or MemberPress, then you don’t need to do any of this as our plugin does all of this for you. For this to work make sure you have the “Ecommerce” setting enabled in the Matomo Analytics tracking settings within your WordPress.