If you are spending on Google Ads without conversion tracking, you are flying blind. This is the step-by-step for wiring up GA4, Google Ads, and your forms so every lead, call, and sale shows up where the money decisions get made.

Before you start

  • Access — Admin or edit rights to your website, plus your Google Ads and GA4 accounts (or the ability to get them).
  • A GTM container — A free Google Tag Manager account so you can manage tags without editing site code every time.
  • An hour, undisturbed — Setup is fast; the testing is where it counts. Block the time so you finish the verify step, not just the setup.

1. Decide what counts as a conversion

Before you touch any code, list the actions worth money: a form submit, a phone call, a booking, a purchase. Pick the two or three that genuinely signal a lead, not vanity clicks like a PDF download.

2. Install Google Tag (gtag) via GTM

Create a Google Tag Manager container and drop the snippet in your site head and body. GTM lets you add and edit every tracking tag later without redeploying the site, which is the whole point.

3. Confirm GA4 is receiving data

Add your GA4 Measurement ID as a tag in GTM, publish, then open GA4 Realtime and load a page. If your own visit shows up, the pipe is connected. If not, fix this before going further.

4. Mark the key events as conversions

In GA4, find the events that fire on your money actions (form_submit, generate_lead, purchase). Toggle each one on as a Key event. GA4 only optimises and reports against events you have flagged.

5. Create the conversion action in Google Ads

In Google Ads, go to Goals then Conversions and create an action. The cleanest route is to import your GA4 Key events so Ads and Analytics agree on the same numbers instead of double-counting.

6. Add call and form tracking

For a local business, calls are conversions too. Turn on call-from-ads and website-call tracking, and fire a form-submit event on your thank-you page or form success. Now phone and form leads both count.

7. Verify with a real test conversion

Submit your own form and place a test call. Check Google Tag Assistant, GA4 DebugView, and the Google Ads conversion status. Do not trust a setup until you have watched a real conversion land end to end.