Circular Tag Dependencies
GTM's Tag Sequencing feature lets one tag declare another as a setup tag that must fire first. a cycle in those declarations: Tag A is configured to fire after Tag B, but Tag B is configured to fire after Tag A. GTM resolves cycles by ignoring one side of the dependency, so the actual ordering is non-deterministic and likely wrong.
Why It Matters
GTM has no compile-time validation for tag sequencing cycles. You can create Tag A with setup tag B, then edit Tag B to declare setup tag A, and the GTM UI accepts it silently. At runtime, GTM has to break the cycle somewhere. it does, but the choice is opaque, and the behaviour can change between container versions or even between page loads if other timing factors shift. This is almost always the result of two engineers editing tags in parallel without seeing each other's sequencing configuration. The damage is intermittent. The tags fire in unpredictable order, and any timing dependency between them (Conversion Linker → Conversion Tag) is unreliable. The fix is straightforward: identify the cycle and break it by deciding which tag is genuinely the prerequisite.
How To Fix It
- AdLint's finding details list every cycle (Tag A → Tag B → Tag A).
- For each cycle, open both tags in GTM and identify the Tag Sequencing configuration.
- Decide which dependency is the real one. Usually there is a clear answer (a Conversion Linker is the prerequisite for a Conversion Tag, not the other way around).
- Remove the incorrect Tag Sequencing relationship from the wrong side.
- In Preview mode, fire the tags and confirm they execute in the intended order. Publish.
Example
Cycle:
Tag: Google Ads - Purchase Conversion (Setup tag: Google Ads - Conversion Linker)
Tag: Google Ads - Conversion Linker (Setup tag: Google Ads - Purchase Conversion)
Fix: remove the second setup-tag relationship. The linker does not depend on the conversion tag.A circular Tag Sequencing dependency in this GTM container. Google's Tag Sequencing documentation, sequencing relationships must form a directed acyclic graph for runtime ordering to be deterministic. Circular dependencies cause non-deterministic firing order, which compromises any time-sensitive behaviour built on the sequencing (such as Conversion Linker → conversion tag ordering). Fix: identify each cycle, decide which sequencing edge is genuinely required, and remove the redundant relationship. Source: support.google.com/tagmanager/answer/6238868.
Drop this paragraph into your client deliverable. Sources back to the canonical platform documentation linked below.
References
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