Is it Possible to Change an Existing B/S GL A/C to the P&L Type?

Technically, you will be able to change all the fields, except the account number, of a GL account in the Chart of Accounts area. However, in this particular instance when you change the ‘GL account type’ from ‘B/S’ to ‘P&L,’ make sure that you again run the ‘balance carry-forward’ program after saving the changes so that the system corrects the account balances suitably.