1) It enables the division of work among accounting personnel by assigning with separate books and it increases efficiency of personnel as they perform same activities daily.
2)It helps to save time and labor by recording similar type of transactions in a separate book.
3)It becomes easy to access the detailed information relating to a particular transaction as the transactions relating to one head are recorded in a separate book.
4) It helps to install internal check system as the subsidiary book maintained by a clerk is automatically checked by another clerk.
5) It helps to maintain accounts and thus avoids the necessity of journal entries.
6) The existence of separate books help in the detection of errors quickly in case of disagreement of trial balance..