If you have multiple JIRA instances in your organization, it is sometimes useful to integrate them together, especially when teams from different projects need to collaborate and work together. In this recipe, we will integrate two JIRA instances together so that we can link issues across systems.
Perform the following steps to link two JIRA instances together:
Navigate to Administration | Applications | Application links.
Enter the other JIRA's URL and create the application link. JIRA should automatically detect the target application as JIRA. If, for some reason, it does not, make sure you select JIRA as the Application type when prompted.