You can mark customers you are not currently servicing as Inactive.
To generate a report to show your Inactive customers, go to the "Reports" Tab.
Click "Inactive Customers" under the "Others" section.
Select the Date Range you would like to be on the report.
The inactive customers will show based on the date they were marked inactive. Your report will only show those accounts that were marked inactive during the date range you selected previously.
Once the report is generated, you can export an Excel sheet or CSV file or print the report.