List the measurement tools already installed before adding more tags. A purchase should not be sent once directly to GA4 and again through GTM or another module. Reliable data matters more than the number of pixels.
Map the ecommerce events
Check product views, add-to-cart, checkout, purchase and refund events that matter for your store. GA4 ecommerce events should carry the relevant items, currency, value and a stable transaction identifier for purchases. Compare reported amounts with actual orders.
Validate before relying on reports
Use one delivery path per destination, direct or through GTM, and respect consent. Place a test order, inspect diagnostics and reports, then test refusal of cookies and a refund if relevant. Keep a staging shop for update checks.
Explore the PrestaShop tracking module
Source : Google Analytics documentation.
Verify a transaction before interpreting GA4 reports
After a test order, compare the amount, currency and transaction ID between PrestaShop and the measurement destination. Check that two integrations do not send duplicate purchase events. Test refunds and consent choices. Explain measurement discrepancies before interpreting conversion rates.
Before validating your events, also test refusal and withdrawal using our PrestaShop cookies and GDPR guide. A Consent Mode signal does not replace these checks.