When a client is archived, you can't allocate visits to them.
To archive clients that no longer require an active service on Nursebuddy go to People > Clients then select client name
Click the Edit button on left of screen
Click Service tab
Click in the "Service end/Archive date" field, select the date from the calendar and click Save button
To review your archived clients, go to People > Clients and click the Archived clients button.