1. Direct Solution Assuming sam is the Jira username/account identifier and you want issues assigned to that user: project = CBA AND issuetype = "Server Deinstallation" AND assignee = sam If sam is the user's display name and Jira does not recognize it directly, use the actual Jira username/account ID instead. 2. Root Cause Analysis Your original query: project = CBA AND issuetype ="Server Deinstallation" assigned to "sam has several issues: assigned to is not valid JQL syntax. The correct field is assignee. "sam has an unclosed quotation mark. If sam is intended as a literal username, it should be supplied as the value of assignee, e.g. assignee = sam. issuetype = "Server Deinstallation" is correctly quoted because the issue type contains a space. project = CBA is valid if CBA is the actual project key. If sam is a display name For Jira Cloud, the safest approach is generally to use the user's account ID, for example: project = CBA AND issuetype = "Server Deinstallation" AND assignee = "ACCOUNT_ID" 3. Performance & Compatibility Notes Recommended clause order: project = CBA AND issuetype = "Server Deinstallation" AND assignee = sam Putting the project restriction first is a good practice because it narrows the search scope early. Jira's query optimizer ultimately determines execution details, so clause order should not be treated as a guaranteed performance optimization. Cloud vs. Data Center For this particular query, there is no meaningful Cloud/Data Center syntax difference. project, issuetype, and assignee are standard JQL fields. The main compatibility consideration is user identification: Jira Cloud: account IDs are commonly used for user references. Jira Data Center/Server: usernames may commonly be used, depending on the Jira version/configuration. Custom fields No custom fields are involved here, so you do not need a cf[10001] substitution. If "Server Deinstallation" is actually a custom field value rather than an issue type, then the query would need to use that custom field's actual name or ID instead.