Fix Firing Status “Failed” - Google Tag Manager & Google Ads
Update 19. Feb 2025
I have confirmed that a failed tag in Google Tag Assistant does not necessarily mean the tag failed to send data.
The test above was done by finding real ads, going on incognito, clicking on ad, converting, and waiting a few hours. Tracking works. For me, the failed status was (and still is!) the user-provided data tag used for Google Ads’ “enhanced conversions for leads” which seemed to result in a bug saying Google Ads conversion tags fail although the tags work.
For the first conversion the tags usually work but (the user-provided data event adds some cookie— I haven't yet checked which one as there are so many) that results in the FAILED status for future Google Ads conversions.
(Original blog post starts here)
This week while doing Acuity Scheduling offline conversion tracking for Google Ads, I’ve been struggling with a super annoying problem.
First conversions go through. Next ones fail.
Tested different GTM. Different ad account. Different website.
Looking for answers
The conversion tracking GOAT Simo Ahava had a blog post on failed GTM tags, but unfortunately, those solutions were not relevant here.
Tests
I ran a bunch of tests first without finding the issue.
✅ Not related to consent mode settings or overrides
✅ Not related to Google Ads conversions being set to “once” instead of “every” which would have been the most logical as that’s exactly what’s happening here
✅ Not related to ad blockers or browser profiles
✅ Not due to Google Ads conversions enhanced conversion user data
✅ Not caused by iframe implementation
✅ Tested on multiple Squarespace sites - issue persists
✅ Tested with fresh Google Tag Manager container - problem continues
✅ Tested with different Google Ads conversion IDs - same result
✅ Issue appears to be related to GTM/Google Ads interaction specifically
Solutions
If firing status in Google Tag Manager says “failed”, this may be due to Google Tag Manager user-provided data event which is used for Google Ad’s “Enhanced Conversions For Leads”.
I’m not sure why Failed tags happens with enhanced conversions for leads. It’s probably a bug in Google’s side. But nice to finally know what causes it.
🔑 Key ideas
First Google Ads conversions go through
After GTM user-provided data event all Google Ads conversions say “failed”
Even a new GTM, another website, another Google Ads account does not fix it.
Removing GTM user-provided data event does not help.
Clearing cookies fixes the issue. So we could dig which cookie it is but not sure if it helps.
I believe the tags do work and it’s a bug in GTM.
But not yet 100% sure. It also seems like it first said Fired, then turned into Failed, although I wasn’t able to replicate it as it’s so fast. Would need to record a video.