Mark reminders as completed or incomplete on Mac
To indicate that a reminder is done, mark it as complete. The reminder is saved, but it’s hidden in the list. You can scroll to the top of a list to see its completed reminders.
Mark reminders as complete
In the Reminders app on your Mac, do any of the following:
From a notification: Click Complete in a reminder notification when it appears in the top-right corner of your screen.
One reminder: Select the circle
next to the reminder’s name.Multiple reminders: Select the reminders, then select the circle
next to one of the reminders (or tap 
in the Touch Bar).All reminders in a list: Control-click the reminder list in the sidebar, then choose Complete All Reminders.
If you don’t see the sidebar, choose View > Show Sidebar.
If a reminder is set to have repeated notifications, and you mark it as complete, the reminder for that day moves to the completed section of the list. The reminder for the next repeat date appears in the reminders list.
If you complete a reminder whose last notification you chose to ignore, you won’t be notified about the reminder again. See Respond to reminder notifications.
Mark a reminder as incomplete
You can mark a completed reminder as incomplete so it appears in your reminder list again. If the reminder was set to have repeated notifications, that setting is removed.
In the Reminders app
on your Mac, scroll to the top of the reminder list until you see Completed, then click Show.Do one of the following to mark reminders as incomplete:
One reminder: Deselect the circle
next to its name.Multiple reminders: Select the reminders, then deselect the circle
next to one of their names (or tap in the Touch Bar).All reminders in a list: Control-click the reminder list in the sidebar, then choose Untick All Reminders.
If you see Complete All Reminders instead, hold down Option to see Untick All Reminders.