Google Ads Conversion Tracking Checklist (GA4 & GTM)

Why conversion tracking decides your results

Google Ads bidding is only as smart as the data you give it. Strategies like Maximize Conversions and Target CPA look at which clicks led to conversions and bid more on similar searches. If “conversion” means a page view, a button click or a duplicate count, Google will happily find you more of those, and your cost per real customer goes up.

In our audits, broken or misleading tracking is the most common reason an account never improves. The fixes are usually not complicated. They just need to be done in order and tested properly. Use this checklist from top to bottom.

Step 1: List every way a customer can contact you

Before touching any tags, write down every lead path. Most local businesses have more than they think:

• Contact and quote forms (on each landing page)
• Phone calls from the ad itself (call assets)
• Phone calls from your website (click-to-call and people dialling the number they see)
• Online booking tools
• Chat or messaging widgets
• Purchases, deposits or paid consultations
• Leads from Local Services Ads and Google Business Profile (tracked separately)

For each one, decide: is this a real lead or sale? That becomes a primary conversion. Is it just a sign of interest, like viewing the pricing page? That is secondary, for observation only.

Step 2: Create the right conversion actions

Setting	For leads	For purchases
Goal	Primary for real leads only	Primary
Count	One (per click)	Every
Value	A realistic average value of a lead	The actual transaction value
Click-through window	Match your sales cycle (often 30–90 days)	Match your buying cycle
Attribution	Data-driven where available	Data-driven where available

Step 3: Install tags cleanly with Google Tag Manager

1. Install one Google Tag Manager container on every page of the site.
2. Add the Google tag (for Google Ads and GA4) through Tag Manager.
3. Add the conversion linker tag so click information is stored correctly.
4. Remove old, hard-coded Google Ads or Analytics snippets so nothing fires twice.
5. Publish a version with a clear name, such as “Lead tracking v1 – forms and calls”, so you can roll back.

Step 4: Track forms on real submissions

Fire the form conversion only when a form is actually sent successfully. Good options, from most to least reliable:

1. A thank-you page that only loads after a successful submission, with the conversion firing on that page view.
2. A success event sent by the form (for example a data layer event) when the server confirms the submission.
3. An element-visibility trigger on the success message, if the form shows one.

Avoid firing on the button click. People click Submit with missing fields, click twice, or leave before it sends. Each of those would be counted as a lead.

Step 5: Track phone calls properly

Set the minimum length to what a real enquiry takes in your business. A 20-second call is usually a wrong number or a sales call. For a full walkthrough, see how to track phone calls from Google Ads.

Step 6: Turn on enhanced conversions

Enhanced conversions send a hashed (one-way encrypted) version of details the customer typed into your form, such as their email or phone number, alongside the conversion. Google matches it to signed-in accounts to recover conversions that cookies miss, for example when someone clicks on a phone and converts later on a laptop.

• Enhanced conversions for web improves online conversion measurement.
• Enhanced conversions for leads lets you later upload leads that became customers, matched by the same hashed details, without storing click IDs.

Mention the use of this data in your privacy policy, and collect it only with appropriate consent.

Step 7: Set up consent correctly

Google’s Consent Mode adjusts how its tags behave based on the visitor’s choices in your cookie or consent banner. When a visitor declines, tags can still send limited, cookieless signals, and Google models some conversions it cannot observe.

Step 8: Link GA4 without double counting

Link your GA4 property to Google Ads so you can see engagement data and build audiences. Then decide on one source for each conversion:

• Use the Google Ads conversion tag for your primary lead conversions, or
• Import the GA4 key event instead, but not both for the same action.

Importing a GA4 “form_submit” key event while also firing a Google Ads form tag counts every lead twice, and bidding treats each lead as two.

Step 9: Import offline conversions from your CRM

This is where good tracking becomes great. Not every lead becomes a customer. When you send Google back which leads were qualified and which became sales, bidding can find more of the people who actually buy.

1. Store the click ID (gclid) with each lead in your CRM, or use enhanced conversions for leads.
2. Create conversion actions such as “Qualified lead” and “Closed – won”, with values.
3. Upload results on a schedule, daily or weekly, through a CRM integration, Google Sheets or an upload.
4. Once you have enough volume, make “Qualified lead” or “Closed – won” the primary goal.

Step 10: Test every path

Recheck monthly. Website updates, new plugins and form changes break tracking more often than anything else.

The most common tracking mistakes

• Counting page views, scroll depth or button clicks as primary conversions.
• Importing the same conversion from GA4 and the Google Ads tag.
• Counting “Every” for leads, so one person who submits twice counts twice.
• No minimum call length, so short and wrong-number calls count as leads.
• Forgetting to track calls at all, which hides the channel that brings most local leads.
• Leaving old conversion actions as primary after rebuilding the site.

If you are not sure your tracking is right, our conversion tracking service audits and fixes it.