A purchases day book is an accounting ledger in which purchasing transactions are recorded. This book is most commonly found in manual accounting systems, where purchases are recorded by hand in a ledger. The purchases day book is used to keep purchasing transactions from overwhelming the general ledger, which can be a major problem in a manual record keeping environment. The basic information recorded in a purchases day book is as follows:
- Transaction date
- Name of the supplier
- Supplier invoice number
- Supplier invoice amount
At regular intervals, and always at the end of a reporting period, the transactions in the day book are summarized and carried forward (posted) to the general ledger. If anyone were to research a transaction, they would need to return to the day book in order to find the specifics of a transaction.
A purchases day book is also known as a purchases journal.