Purchases journal definition including break down of areas in the definition. Analyzing the definition of key term often provides more insight about concepts. Purchases journal can be defined as: Journal normally used to record all purchases on credit. Purchases journal is a special journal for a specific purpose, specific transaction, purchases journal being used to record purchases on account. A purchases journal can be used in a manual accounting system to simplify the process, allowing the recording of purchases without having to record the debit and credit to the general journal and then post each transaction. The purchase journal allows similar purchases to be recorded in one place and then be summarized and posted to the system at the end of the period.