What to check before you touch anything
- The practical way to check this is through Report Editor (or a standard report) broken out by Conversion Action, using the "All Conv. Value" metric. Building a report segmented by specific conversion action and comparing count/value per action makes it easy to spot whether the same purchase is being double-counted across multiple conversion actions (say, between the native Google Ads tag and a GA4 import) — in that case, the account's total "All Conv. Value" will noticeably exceed real revenue, and the breakdown by conversion action will show that several different actions are, in effect, recording the same transactions.
- How many times does the conversion tag fire on the order confirmation page? Open the "thank you for your order" page directly (refresh it, or hit the browser's back button and return to it) and use Google Tag Assistant or a tag-debugging extension to check whether the conversion fires again on every reload.
- Are there multiple conversion sources set up for the same action at once — say, a native Google Ads tag configured manually via GTM alongside a GA4 conversion import set up as a separate conversion in Google Ads? Then a single purchase could be counted twice under two different conversion action names (this is exactly what the Conversion Action breakdown above will reveal).
- Is a conversion being double-counted between your website and app for the same purchase (relevant if you have both a site and a mobile app with its own SDK)?
- Does the number of conversions in Google Ads match the number of real transactions in your CRM/e-commerce platform over the same period? A consistent percentage overshoot (rather than one-off spikes) is a telltale sign of systematic duplication rather than random noise.
- Is the tag firing on promo pages, payment-error pages, or test orders (including ones placed internally by your own team)? These can pile up in your conversion stats over time, inflating both the count and the value.
Possible approaches
- If the Conversion Action breakdown in Report Editor shows several actions recording the same transaction, pick one primary source for bid optimization (usually whichever one most accurately reflects real transactions) and either disable the duplicate or move it to "observation only" (secondary) status, so it doesn't feed into optimization or get summed into the total value.
- If you find the tag firing again on page refresh/re-visit, the standard fix is to tie the tag's firing to a unique transaction ID and set up deduplication, so the same transaction can never be counted twice.
- Google recommends using a transaction ID as the built-in safeguard against duplication — it's a standard feature of the e-commerce conversion tag, and its absence in your current setup is itself a red flag.
- A regular check (say, monthly) — through that same Conversion Action report with All Conv. Value — comparing Google Ads' conversion count and value against your e-commerce/CRM platform's data is a simple, effective way to catch duplication before it accumulates and distorts months of optimization based on inflated numbers.
- If test/internal orders are landing in your stats, set up an exclusion for them (by IP, by a special parameter, by test environment) at the tag level, rather than assuming their volume is "too small to matter" — over months, that can add up to a noticeable distortion.