Google’s own documentation confirms that its data-driven attribution engine silently drops offline conversions uploaded more than seven days after the conversion event, even though the standard reporting columns advertisers check every day keep counting them. The result is two different totals for the same campaign, from the same account, depending only on which report gets opened.
Per Google’s own Ads Help documentation, “if an offline conversion is uploaded more than 7 days after the initial event took place, it is bypassed by the attribution modeling calculations.” The same page confirms Model Comparison also excludes Search Partner Network, Gmail and App conversions entirely, categories standard reporting counts without restriction. Google frames the window as necessary for its rolling attribution calculations, but the effect is that any advertiser with a lag between click and CRM-confirmed sale, most B2B pipelines included, is measuring against a model that structurally cannot see a real share of its own conversions.
Why it matters: attribution and Smart Bidding share the same engine. A conversion the model never sees also never informs the automated bidding that is supposed to chase more like it, the same automated-bidding default Microsoft Ads is now pushing advertisers toward. A sales team that batches CRM uploads weekly, a common and reasonable rhythm, can be feeding Smart Bidding a permanently incomplete picture while the standard dashboard shows a totals column that looks complete and flags nothing.
The original insight is less about the seven days and more about where Google disclosed it: a help center answer, not a product update or an in-product warning. Nothing in Model Comparison itself flags the exclusion, so operations teams only find the gap by independently reconciling two reports Google never says should disagree. Given how much B2B teams already distrust the data behind their budgets, the fix is straightforward: push CRM conversions inside the seven-day window, or treat Model Comparison’s read on offline-heavy campaigns as directional until Google closes the gap or surfaces it in the product itself.
Source: Google Ads Help
