How to Set Up GA4 Ecommerce Tracking: Complete Event Reference

GA4 Ecommerce Event Architecture

GA4 ecommerce tracking uses a specific set of recommended event names and parameter structures. Using the correct event names is critical — GA4's built-in ecommerce reports (Monetisation section) only populate with data when you use the exact recommended names and include the required parameters.

The Items Array

All GA4 ecommerce events include an items array — a list of product objects. Each product object should include:

• item_id (required): your product SKU or unique identifier
• item_name (required): product name as it appears in your catalogue
• quantity: quantity of this item
• price: unit price of the item
• item_brand: brand name
• item_category: primary category
• item_category2 through item_category5: subcategory hierarchy
• item_variant: variant (e.g. colour, size)
• item_list_name: name of the product list (used in list attribution reporting)
• index: position of the item in the list

Product List Events

view_item_list: User views a list of products (category page, search results)

gtag('event', 'view_item_list', {
  item_list_id: 'category_shoes',
  item_list_name: 'Shoes',
  items: [{item_id: 'SKU-001', item_name: 'Running Shoe', price: 89.00, index: 1}]
});

select_item: User clicks a product from a list

Product Detail Events

view_item: User views a product detail page

gtag('event', 'view_item', {
  currency: 'GBP',
  value: 89.00,
  items: [{item_id: 'SKU-001', item_name: 'Running Shoe', price: 89.00, quantity: 1}]
});

Cart Events

add_to_cart: User adds an item to the cart

remove_from_cart: User removes an item from the cart

view_cart: User views the cart

All cart events require the items array, currency, and value parameters.

Checkout Events

begin_checkout: User initiates the checkout process

add_shipping_info: User selects shipping method

add_payment_info: User selects payment method

These events power the checkout funnel in GA4's Monetisation reports.

Purchase Event

purchase: Transaction completed

gtag('event', 'purchase', {
  transaction_id: 'T-12345',
  value: 89.00,
  currency: 'GBP',
  tax: 14.83,
  shipping: 4.99,
  coupon: 'SALE10',
  items: [{
    item_id: 'SKU-001',
    item_name: 'Running Shoe',
    price: 89.00,
    quantity: 1,
    coupon: 'SALE10',
    discount: 9.90
  }]
});

Required for the purchase event: transaction_id, value, currency, and items.

refund: Full or partial refund processed (use negative value for the refunded amount)

GA4 Ecommerce Reports That Need This Data

With correctly implemented ecommerce events, GA4 populates:

• Reports then Monetisation then Ecommerce purchases: revenue by product, brand, category
• Reports then Monetisation then Purchase journey: funnel from view_item_list to purchase
• Reports then Monetisation then Checkout journey: funnel from begin_checkout to purchase

Summary

GA4 ecommerce tracking requires using the exact event names from the spec and including the items array on every event. The purchase event is the most critical — always include transaction_id for deduplication, value, currency, and items. Without these, the built-in Monetisation reports remain empty.

See our Enhanced Ecommerce Tracking service and GA4 Setup & Audit service for ecommerce implementation.

Need GA4 ecommerce tracking set up correctly? Contact Adslytics.