It isn't currently possible to merge separate two ledger vouchers. If user want to change the ledger name of a voucher, he have to do it only through voucher entry screen in alter mode individually. At the time of making balance sheet, user has to shift many vouchers from one head to another head on the call of auditors. With this modules user can shift ledger vouchers of a ledger to another required ledger individually or all by selecting them.          

Note: This add-on will work only “Accounts only”