Tally 9 allows users to record memorandum vouchers which is a non accounting voucher and entries through a memorandum voucher in tally 9 does not affect the accounting books.
In other words, Tally.ERP 9 does not post memorandum vouchers to ledgers, but stores them in a separate Memorandum Register.Memo vouchers can be of any kind, i.e. receipts entry, payments, sales,purchase or even journal entry You can alter and convert a Memo Voucher into a regular voucher when you decide to bring the entry into your books. Memo voucher is useful for passing temporary entry in books which are of such nature that does not affect the accounts, however the user should know and can make the regular entries for the same.
let me give you an instant example, you have issued/received post dated cheques, then you should post such cheques in the books of account through memorandum