Atlassian does not support JIRA downgrades. If you wish to downgrade the edition of your JIRA installation, please refer to the appropriate instructions below. Atlassian strongly recommends that you do not attempt to downgrade the version of your existing JIRA installation.

We recommend that you do not downgrade your edition of JIRA, (i.e. from JIRA Professional or JIRA Enterprise to JIRA Standard, or from JIRA Enterprise to JIRA Professional), as it is a non-trivial process that requires significant manual intervention.

In some places we link directly to the child pages rather than to the main one. Also, people intend to perform a search for something like "downgrading from JIRA enterprise to professional" and never have opportunity to review the warning on the main page.

Finally, if the experience any issue with the downgrade they log a case in SAC where they get surprised by feedback about our policy.

The following pages should be updated:

http://www.atlassian.com/software/jira/docs/latest/enterprise_to_pro.html
http://www.atlassian.com/software/jira/docs/latest/enterprise_to_standard.html
http://www.atlassian.com/software/jira/docs/latest/pro_to_standard.html