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Quick answer: Create a conversion action in Google Ads, add a Conversion Linker tag and a Google Ads Conversion Tracking tag in GTM with your Conversion ID and label, pass a value and transaction ID for purchases, turn on Enhanced Conversions, and test with Tag Assistant. Then set only real business outcomes as primary goals.
Why conversion tracking decides your results
Smart Bidding learns from the conversions you report. If those conversions are duplicated, missing or not tied to real value, the algorithm optimises for the wrong thing and your cost per result climbs. Clean tracking is the cheapest performance improvement you can make.
Step 1: Create the conversion action
In Google Ads, go to Goals, then Conversions, then New conversion action and choose Website. Pick the category (Purchase, Submit lead form, Book appointment), set the value and the counting method. Use Every for purchases and One for leads.
Step 2: Add the tags in GTM
- Conversion Linker: fire on all pages so the click ID is stored.
- Google Ads Conversion Tracking: add the Conversion ID and Conversion Label, and fire it only on the real success event, for example the thank you page or a
purchasedataLayer event.
Step 3: Send values and transaction IDs
For ecommerce, pass the order value, currency and a unique transaction ID from the dataLayer. The transaction ID stops the same order from being counted twice when a customer reloads the confirmation page.
Step 4: Turn on Enhanced Conversions
Enhanced Conversions sends a hashed version of the customer’s email or phone number with the conversion. Google uses it to match more conversions to ad clicks. Enable it in the conversion settings and map the user data in GTM.
Step 5: Clean up your goals
Many accounts have old or duplicate conversion actions set as primary. Keep the real outcomes as primary and move micro actions, such as page views or scrolls, to secondary so they are visible but do not drive bidding.
Step 6: Test before you trust it
Use GTM Preview and Tag Assistant to confirm the tag fires once per conversion. In Google Ads, the conversion status can take a few hours to update after the first recorded conversion.
FAQ
Should I import GA4 key events or use the Google Ads tag?
The Google Ads tag is usually more accurate and faster for bidding. GA4 imports are useful as a secondary view or for simpler setups.
How do I track phone calls?
Use call extensions for calls from ads and a click trigger on phone links for calls from your website.
What about leads that close offline?
Capture the GCLID with the lead and import the closed deals back into Google Ads as offline conversions.
Need your conversions fixed? See my Google Ads tracking service.
