How do you set up conversion tracking and e-commerce tracking in GA4?

Conversions (key events): any event can be marked as a conversion in Admin, or from the Events report with a toggle. Because GA4 is event-based, this is far more flexible than Universal Analytics goals — but it also means the event must exist and fire correctly first.

E-commerce tracking requires specific recommended events with specific parameters, pushed to the data layer and picked up by GTM:

• view_item_list, view_item, select_item
• add_to_cart, remove_from_cart, view_cart
• begin_checkout, add_shipping_info, add_payment_info
• purchase — with transaction_id, value, currency, and an items array

The names and parameter structure must match Google's specification exactly. Renaming them means the e-commerce reports stay empty, and this is the most common implementation failure.

Essential checks:

• transaction_id must be unique per order — it is what deduplicates purchases if a user refreshes the confirmation page. Without it, revenue inflates.
• Exclude your payment gateway as a referral, or the session will break at checkout and attribute the sale to the gateway.
• Verify in DebugView and by completing a real test purchase, then reconcile totals against the order system.

Note: Currency must be a valid ISO code and consistent, or values are misinterpreted. And mark only genuinely meaningful actions as conversions — flagging every event makes the concept meaningless.