Prevent Duplicate Sub-tasks Creation in Jira Automation

[Automation Tester]

Hi,

I’ve set up Jira automation to create three sub-tasks (Sub-task 1, 2, and 3) when the issue transitions from Sizing → On Deck. However, if the status moves back to Sizing and then again to On Deck, the same sub-tasks are recreated.

How can I configure the automation to prevent duplicate sub-tasks from being added if they already exist?

Thanks!

[Tim W]

Hi,

I had to do something similar to a twilio x jira itsm connection I did earlier this year, because it would create the same subtask when they would get disconnected, but anyways try this: 

Trigger

• Issue transitioned → From: Sizing → To: On Deck

• (Optional) Re-fetch issue data

Lookup existing sub-tasks

• Lookup issues with JQL:

  issuetype = Sub-task AND parent = {{issue.key}} AND (summary = "Sub-task 1" OR summary = "Sub-task 2" OR summary = "Sub-task 3")

Create only what’s missing

Use three separate IF blocks so you can create more than one in the same run.

• IF {{lookupIssues.summary}} does not contain Sub-task 1
  → Create issue (Sub-task) → Summary: Sub-task 1

• IF {{lookupIssues.summary}} does not contain Sub-task 2
  → Create issue (Sub-task) → Summary: Sub-task 2

• IF {{lookupIssues.summary}} does not contain Sub-task 3
  → Create issue (Sub-task) → Summary: Sub-task 3

---

Labels are you best friend!!!
If titles might change, tag created sub-tasks and check for the tag instead of the summary text.

• When creating each sub-task, set Labels: auto-created

• Before each creation, add Related issues condition → Sub-tasks → None match JQL:

  labels = auto-created AND summary = "Sub-task 1"

Result: Re-entering On Deck won’t duplicate existing sub-tasks; the rule only adds whichever ones are missing.