Define the action before the event
Write down what constitutes a qualified request, booking, or purchase. Distinguish form start, validation, and actual confirmation.
Test in the browser and GA4
Use GTM preview, DebugView, and application logs. Check errors, blockers, consent, and duplicate firing.
Reconcile with an operating source
Compare events with emails, CRM entries, appointments, or transactions. Differences may be legitimate, but they should be understood.
Document the convention
Keep the name, condition, parameters, source, and owner for each event. Undocumented measurement decays quickly.
This guide provides a general starting point. A diagnosis must account for the actual site, access, data, and constraints before any change.