The 30-Day Limit
The Trash bin in macOS is designed as a temporary holding area for deleted files, giving you a grace period to recover a document or image if you change your mind. However, macOS includes a built-in storage optimization feature that changes how the Trash operates. If this feature is active, your Mac will automatically empty the Trash, permanently deleting any files that have been sitting there for more than 30 days. While this is an excellent way to effortlessly maintain free space on a small hard drive, it can be a nasty surprise if you treat the Trash bin like an archive folder and suddenly realize a month’s worth of deleted data is gone forever.
Disabling the Automatic Trash Deletion Schedule
To retain your deleted files indefinitely and stop macOS from automatically emptying the Trash after 30 days, you must adjust the Finder’s advanced preferences.
Click anywhere on your desktop to ensure Finder is the active application (you should see “Finder” in the top-left corner of the menu bar). Click on the word Finder in the menu bar and select Settings… (or Preferences… on older macOS versions). In the window that opens, click on the Advanced tab (the gear icon). Look down the list of options for a checkbox labeled Remove items from the Trash after 30 days. Click this checkbox to uncheck it. You can now close the settings window. From this point forward, items moved to the Trash will remain there indefinitely, taking up hard drive space, until you manually right-click the Trash icon and select “Empty Trash.”