Google Ads Conversion Tracking: Common Mistakes

Your Google Ads dashboard shows 200 conversions this month. Looks great. But is that number accurate?

For most agencies, the answer is "probably not." Google Ads conversion tracking has several common mistakes that inflate numbers, miss conversions, or misattribute results. If your tracking is wrong, every optimisation decision you make is based on bad data.

Here are the most common Google Ads conversion tracking mistakes — and how to fix them. For GA4-specific setup, see our [GA4 conversion tracking guide](/blog/setting-up-ga4-for-accurate-conversion-tracking).

Mistake 1: Duplicate Conversion Tags

This is the most common and most damaging mistake.

Your developer installs the Google Ads conversion tag on the thank-you page. Then someone else installs it again through Google Tag Manager. Now the tag fires twice every time someone converts.

Google Ads counts each tag fire as a separate conversion. If you had 100 real conversions, Google Ads now shows 200.

How to check

1. Open the thank-you page in Chrome
2. Right-click > View Page Source
3. Search for "google_conversion" or "gtag"
4. If you find the tag code twice (once in the source code and once in GTM), you have a duplicate

How to fix

Remove one of the two tags. If you are using GTM, remove the hardcoded tag from the page source. Pick one method and stick with it.

Mistake 2: Wrong Attribution Window

Google Ads default attribution window is 30 days for clicks and 1 day for views. This means if someone clicks your ad and converts 25 days later, Google claims it.

For most Indian businesses, 30 days is too long. The bigger problem is when agencies accidentally change the window without realising it. A 90-day click window means Google claims conversions from people who clicked your ad three months ago.

How to check

Go to Google Ads > Tools & Settings > Conversions > Click on your conversion action > Check the "Count" and "Window" settings.

Mistake 3: Not Using Enhanced Conversions

Enhanced conversions is a feature that sends hashed first-party data (email, phone number, name) from your conversion page to Google. Google matches this data with logged-in Google users to attribute conversions more accurately.

Without enhanced conversions, Google relies on cookies alone. Since browsers block third-party cookies and users clear cookies regularly, many conversions go unattributed.

Why this matters in India

Indian users frequently switch between mobile and desktop. They might click an ad on their phone, then convert on their laptop. Without enhanced conversions, Google cannot connect these two sessions. With enhanced conversions, the email address links them.

How to enable

1. Go to Google Ads > Tools & Settings > Conversions
2. Click on your conversion action
3. Scroll to "Enhanced conversions"
4. Select "Turn on enhanced conversions"
5. Choose your implementation method (Google Tag Manager recommended)

Google reports that enhanced conversions improve conversion measurement by 5-15%. For Indian agencies, this number is often higher because mobile-to-desktop cross-device behaviour is more common.

Mistake 4: Missing Cross-Domain Tracking

Your client's website is on example.com. The purchase happens on checkout.razorpay.com or payu.in. Without cross-domain tracking, Google Ads cannot connect the ad click to the payment.

The result: Google Ads counts the click but not the conversion. Your conversion rate drops. Your CPA looks terrible. You think the campaign is not working and pause it. But the campaign was working — your tracking was broken.

How to set up cross-domain tracking

If you use Google Tag Manager, add the payment gateway domains to your GA4 Configuration tag's cross-domain settings. GTM will automatically add linker parameters to URLs.

How to verify

Start a session on the main website. Click through to the payment gateway. Complete a test transaction. Check if Google Ads records the conversion.

Mistake 5: Conversion Tag On The Wrong Page

The conversion tag should fire on the page that confirms the conversion happened — the thank-you page, the confirmation page, the order-complete page.

Common mistakes:

Tag on the form page instead of the thank-you page. The tag fires when someone sees the form, not when they submit it. Every page view counts as a conversion.

Tag on a page that redirects. The confirmation page redirects to the home page before the tag fires. The tag never fires. Zero conversions.

Tag fires on page load instead of on form submit. If the tag is attached to the page and not the form submission event, it fires even if the user does not submit the form.

How to fix

Use Google Tag Manager to trigger the conversion tag only when the form is actually submitted. Create a new trigger in GTM, choose "Form Submission," set conditions to match only the conversion form, and attach this trigger to your Google Ads conversion tag.

Mistake 6: Not Linking Google Ads and GA4

Google Ads and GA4 are separate systems. If they are not linked, you are flying blind.

When linked, Google Ads conversion data flows into GA4 and GA4 audiences flow into Google Ads. Without the link, you cannot compare Google Ads conversions with GA4 conversions.

How to link

1. Go to GA4 Admin > Product Links > Google Ads Links
2. Click "Link"
3. Select your Google Ads account
4. Enable "Personalised Advertising" and "Auto-tagging"
5. Save

Auto-tagging must be enabled. Without it, Google Ads does not pass the gclid parameter to your website, and GA4 cannot attribute sessions to Google Ads clicks.

Mistake 7: Counting Soft Conversions As Hard Conversions

A "hard" conversion is the action your client cares about most — a purchase, a qualified lead, a booked appointment. A "soft" conversion is a step in the funnel — a page view, a video watch, a brochure download.

If you count soft conversions in the same bucket as hard conversions, your Google Ads numbers look amazing but your client's actual business results do not match.

How to fix

Separate your conversion actions in Google Ads > Tools & Settings > Conversions. Set primary conversions to "Primary" and secondary conversions to "Secondary." Google Ads will only optimise bidding for primary conversions.

The Accuracy Check

After fixing these issues, compare your numbers:

If Google Ads shows 40%+ more conversions than GA4, something is still broken. Fix it before making budget decisions based on those numbers.

Frequently Asked Questions

Why does Google Ads show more conversions than my CRM?

Google Ads uses attribution models that credit conversions to ad clicks within a 30-day window. It also counts view-through conversions. Your CRM only counts leads that were actually received. A 15-20% gap is normal. Above 30% suggests duplicate tags or a tracking issue.

How do I check for duplicate Google Ads conversion tags?

Open the conversion page in Chrome, right-click and view page source, then search for "google_conversion" or "gtag." If the code appears twice (once hardcoded and once in GTM), you have a duplicate. You can also use the Google Tag Assistant Chrome extension.

What is enhanced conversions in Google Ads and should I enable it?

Enhanced conversions send hashed user data (email, phone) from your conversion page to Google. Google matches this with logged-in users to attribute conversions more accurately, especially across devices. You should enable it — it improves conversion measurement by 5-15%.

How do I fix Google Ads conversion tracking for Razorpay or PayU?

Set up cross-domain tracking so Google Ads can connect the ad click on your website to the payment on the gateway. In Google Tag Manager, add the payment gateway domain to your GA4 Configuration tag's cross-domain settings. Also place the conversion tag on the payment confirmation page.

Get Accurate Numbers Across All Platforms

Tracking mistakes inflate your numbers. Inflated numbers lead to wrong decisions. Wrong decisions waste your client's budget.

ADsHisaab pulls data from Google Ads, Meta Ads, and GA4, and shows all three side by side. If your Google Ads numbers look suspiciously high compared to GA4, the discrepancy percentage will flag it immediately.

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