When i have a test case that exists in TestRail how do i link it to a new user story in Jira?
you can enter the ID of the JIRA story in the “Reference” field - assuming you have configured the JIRA integration.
Yep, we recommend using the References field to link test cases to JIRA issues and you can also enter multiple issue ID by separating them via comma. Issues for defects/bug can be tracked via the Defects field on the Add Result dialog and the Push/Lookup feature in TestRail lets you add and view issues directly from TestRail’s user interface:
For the full two-way integration between JIRA and TestRail, we can recommend our official JIRA add-on: