Google Analytics 4: The Complete Setup Guide

Google Analytics 4 has been the standard analytics platform since Universal Analytics was shut down in 2024. Yet in our experience, more than 80% of businesses we audit have GA4 set up incorrectly — missing conversions, double-counting sessions, or tracking data that simply can't be trusted. This guide covers how to do it right.

Why Most GA4 Setups Are Wrong

GA4's event-based model is fundamentally different from Universal Analytics. Many businesses either migrated their old setup directly (bringing all its errors with them) or used the automatic migration tool, which doesn't configure conversions or custom events. The result is a dashboard full of data that looks complete but is missing the most important information: what actions visitors are actually taking on your site.

Step 1: Create Your GA4 Property Correctly

If you don't have GA4 set up yet, go to analytics.google.com → Admin → Create Property. Choose "Web" as the platform and enter your website URL. Make sure you're creating a GA4 property, not a Universal Analytics one (the option for UA is hidden but still accessible — don't use it).

Set your reporting time zone to your local time zone, not UTC. Set your currency to your local currency. These seem minor but affect every report you'll ever look at.

Step 2: Install via Google Tag Manager

Don't install the GA4 tracking code directly on your website. Use Google Tag Manager (GTM) instead. GTM gives you a single container tag on your site, through which you manage all tracking without touching your website's code for every change. This is especially important as you add more tracking over time.

In GTM, create a new GA4 Configuration tag with your Measurement ID (found in GA4 → Admin → Data Streams). Set it to fire on All Pages.

Step 3: Configure Conversion Events

This is where most setups fail. GA4 tracks many events automatically (page views, scrolls, clicks), but it has no way of knowing which events matter to your business. You need to tell it.

Common conversions to configure:

• Form submissions — contact forms, quote requests, newsletter signups
• Phone number clicks — especially important for local businesses
• Email link clicks
• Thank you page views — if your forms redirect to a confirmation page
• Purchase completions — for e-commerce
• Booking completions — for service businesses

In GA4, go to Admin → Events → Mark as conversion for any event you want tracked as a conversion. If the event doesn't exist yet, you'll need to create it in GTM first.

Step 4: Set Up Custom Events in GTM

For events that GA4 doesn't track automatically, you need to create them in GTM. For a contact form submission, the approach depends on your form: if it redirects to a thank-you page, use a Page View trigger on that URL. If it submits via AJAX (no page reload), you'll need to use the Form Submission trigger or a custom GTM trigger based on a data layer push from your developer.

Step 5: Exclude Internal Traffic

Your own visits to your website will inflate your traffic data and skew your conversion rates. Create an IP address exclusion in GA4: Admin → Data Streams → your stream → Configure tag settings → Define internal traffic. Enter your office and home IP addresses. Then in Admin → Data Filters, activate the Internal Traffic filter.

Step 6: Enable Google Signals

Google Signals links GA4 data with Google account data, enabling cross-device tracking and demographic reporting. Enable it in Admin → Data Settings → Data Collection → Google Signals. Note: this requires user consent under GDPR, so ensure your cookie consent setup is correct before enabling.

Step 7: Link Google Search Console

Linking Search Console to GA4 gives you organic keyword data directly in your analytics — showing which search terms bring visitors and how they behave once on your site. Do this in Admin → Search Console Links.

Step 8: Build Custom Reports

GA4's default reports are too generic for most businesses. Build custom reports in the Explore section that answer your specific questions: which traffic sources drive conversions, which pages have the highest drop-off, which geographic areas generate the most enquiries. Save these as your dashboard and check them weekly.

Validate Everything

Before considering your setup complete, use GA4's DebugView (Admin → DebugView) with GTM's Preview mode to verify every event fires correctly, conversions are tracking, and no events are duplicating. Check that your real-time reports show data when you visit your own site. Don't trust a setup you haven't verified end to end.

The Ongoing Commitment

GA4 setup isn't a one-time task. As your website changes — new forms, new pages, new goals — your tracking needs to update with it. A quarterly analytics audit ensures your data stays accurate and actionable as your business evolves.