Your Google Ads conversions are probably counted twice
The most common tracking mistake we find in audits — and it quietly inflates ROAS, misleads bidding, and makes every decision after it wrong.
In almost every second account we audit, the conversion numbers in Google Ads are higher than what the business actually sold. Not by a little — often by 30–100%. Nobody did it on purpose. It happens because two perfectly reasonable setups were added at different times, by different people.
How it happens
Someone installs the Google Ads conversion tag on the checkout. Months later, someone else links GA4 and imports the GA4 purchase event into Google Ads. Both are set as primary conversions. Google Ads now counts every sale twice — once from its own tag, once from GA4 — and the Conversions column shows the sum.
Smart bidding optimises to that column. So the algorithm thinks campaigns are twice as efficient as they are, and bids accordingly.
The other usual suspects
- Thank-you page reloads or revisits firing the purchase event again, with no transaction ID to de-duplicate it.
- Lead conversions set to count 'Every' instead of 'One' — one person submitting a form twice becomes two leads.
- Micro-conversions (newsletter sign-ups, page views, add-to-cart) left as primary, so bidding chases cheap actions instead of sales.
- A GTM trigger on 'All pages containing /thank-you' that also matches a blog post URL.
How to check in ten minutes
- Go to Goals → Conversions → Summary and look at which actions are marked Primary. There should usually be one per real business outcome.
- Compare last month's Google Ads conversions with your actual orders or CRM leads from paid search. A gap above ~15% needs explaining.
- Make sure your purchase tag sends a transaction ID — Google Ads uses it to drop duplicates.
Fix the counting before you change bids, budgets or campaigns. Every optimisation built on inflated numbers has to be undone later.
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