In order to Close a project, you must change the Operational Stage located in the Settings tab of the desired Project. Please note, that this will not remove the project from your portal, but will update the status from Active to Archived.

Step 1: Select the desired Project to Close from the Project home page:

Step 2: Navigate to the Settings tab and click Accounting Settings:

Step 3: Change Operational Stage to Archived/Closed. Make sure to click Save Changes at the bottom of the page.