The Non Accounting/Unconventional Vouchers are the special vouchers that are used to record provisional or non-accounting transactions. Unconventional vouchers are mainly used to exclude unnecessary entries or provisional entries from the books of accounts and make them available for what if (future reports, projections, forecasts etc.) reports required at any given time.
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Predefined Non Accounting Vouchers in Tally.ERP 9
Using Optional Vouchers in Scenario Management