A CA or Auditor often needs to modify his clients' books of accounts. However this may lead to confusion for the client.

In Tally.ERP 9, there is the Marked Changed Vouchers feature which enable the consultant and client to identify the changes made. 

This feature helps the CA to keep the track of changes of the Transaction without hampering the current transactions of the client. 

Watch this video to learn how to activate the Mark Changed Vouchers feature in Tally.ERP 9.