Hi everyone,
I’m running into what looks like a hard limitation (or bug) with the MailerLite ↔ Zapier integration and would appreciate confirmation.
Context:
• Trigger: Tally form
• Logic: Code by Zapier calculates a result and outputs a valid MailerLite group ID (verified, correct ID)
• Goal: Add subscriber to a dynamic MailerLite group based on the result
What works:
• Create/Update Subscriber with a static group ID
• Adding everyone to a “Completed” group manually
What does NOT work (always errors with groups.0 is invalid):
• Create/Update Subscriber with dynamic group ID
• Add Subscriber to Group with dynamic group ID
• Formatter / Utilities (line items)
• Find Group by Name → pass result to next MailerLite step
The JS logic is correct and the IDs are valid — the failure only happens when the group ID is dynamic.
From what I can tell, the only reliable solution is using Webhooks by Zapier to call the MailerLite API directly, but that’s locked behind the Pro plan.
Question:
Is this a known limitation of the MailerLite Zapier app on the Free plan?
Or is there any supported way to dynamically assign groups without Webhooks / Pro?
