com. law. A book used by merchants with their customers, in which an entry of goods sold and delivered to a customer is made. 2. It is kept by the buyer, and sent to the merchant whenever he wishes to purchase any. article. It ought to be a counterpart of the merchant’s books, as far as regards the customer’s account. 3. Among English bankers, the term pass-book is given to a small book made up from time to time, from the banker’s ledger, and forwarded to the customer; this is not considered as a statement of account between the parties, yet when the customer neglects for a long time to make any objection to the correctness of the entries he will be bound by them.