GA4 and Google
Tag Manager setup

Why a GA4 and Google Tag Manager setup is worth doing properly

GA4 replaced Universal Analytics in 2023 and works differently: everything is an event, and nothing counts as a conversion until someone decides it should. A default installation records page views and a few automatic events, then stops. It doesn't know that a click on your phone number is a lead, that a thank-you page means a form was sent, or that one booking is worth more than ten newsletter signups.

A proper GA4 and Google Tag Manager setup fixes that. It defines your key events, sends them to the ad platforms that need them and makes sure each one fires exactly once. The difference shows up in your ad results within weeks, because Google Ads and Meta finally learn which clicks turn into customers.

What I track for a typical service business

For a contractor, clinic or professional firm, the measurement plan usually looks like this:

• form submissions, each form separately if they mean different things (quote request vs. job application);
• click-to-call on mobile, and clicks on email and WhatsApp links;
• bookings from an online booking system, if it allows tracking;
• important page views, such as pricing or a service area page, as secondary signals;
• scroll and engagement only where it helps a decision, not by default.

For an online store, purchases with revenue, add-to-cart and checkout steps take the lead. Either way, the list is short on purpose. Twenty "conversions" make ad optimization worse, not better.

Naming and documentation

The most common problem in inherited setups isn't missing tags. It's tags nobody can identify. "Tag 14", "FB new", "conversion test copy". When the next person opens the container, they can't tell what's safe to delete. I name every tag, trigger and variable consistently, add notes, and leave a short document listing what is tracked and how. That document is the difference between a setup that lasts years and one that gets rebuilt at every agency change.

Mistakes I fix in most inherited setups

• GA4 installed twice, once by the theme and once through Tag Manager, doubling every page view;
• a thank-you page that can be reached without sending the form, so bookmarks count as leads;
• call clicks tracked on desktop, where nobody taps a phone link, but not on mobile;
• Google Ads importing a GA4 event and also counting its own tag for the same action;
• internal traffic from the owner and staff counted as customers;
• a time zone set to the agency's country, which shifts every daily report.

Each of these is small. Together they make reports unreliable enough that nobody trusts them, which is worse than having no reports at all.

Connecting Google Ads and Meta

Google Ads can import GA4 key events or use its own conversion tag. I usually use the Google Ads tag for primary conversions because it supports enhanced conversions: hashed email or phone from a form, which improves matching when cookies are limited. For Meta, the Pixel goes through Tag Manager with standard events like Lead or Purchase. If your Meta budget is significant, the Meta Pixel and Conversions API page explains the server-side layer that recovers lost signals.

Consent and privacy

Tags have to behave according to each visitor's consent choice. Consent Mode connects your cookie banner with Google's tags, so they adjust automatically. In the US, whether you need a banner depends on state law and your audience, and that call belongs to your attorney. For healthcare sites, I keep tracking on patient-facing pages to a minimum because of HIPAA concerns.

After the setup

Within a few days you'll see leads by source in GA4, and the ad platforms start receiving conversion data. If you'd like all of this in one view with your ad spend, Looker Studio reporting builds on the same setup. If you're unsure whether your current tracking is salvageable, an analytics audit answers that before you spend anything. And if you'd rather understand GA4 yourself first, start with GA4 for small business owners.