Get there: More > Tools > Patrons and Circulation > Overdue Notice/Status Triggers
In order to send the overdue notices that you defined using the Notices tool, you need to first set the triggers to have these messages.
In order to have overdue notices sent to your patrons, you need to set that patron category to require overdue notices.
The Overdue Notice/Status Triggers tool gives the librarian the power to send up to three notices to each patron type notifying them of overdue items
Delay is the number of days after an issue is due before an action is triggered.
If you want Koha to trigger an action (send a letter or restrict member), a delay value is required.
To send additional notices, click on the tabs for 'Second' and 'Third' notice
If you would like to prevent a patron from checking items out because of their overdue items, check the 'Restrict' box, this will put a notice on the patron's record at checkout informing the librarian that the patron cannot check out due to overdue items.
See a Sample Overdue Notice