In considering the operation of the various departments, reference has been made to the use of ticklers for making temporary entries of daily transactions and also registers for posting more permanent data. These books may be either bound or loose-leaf in form. The bound book is a more enduring record and less subject to alteration, but it is not so flexible as the loose-leaf folder, which can be expanded by additional carbon slips or tickets. The latter style of accounting, together with the "block proof" for segregating errors, is being extensively adopted by American banks.

Whenever the records of the departments affect the accounts of customers, corresponding entries are made in the individual ledgers, which are divided according to the several classes of depositors, including individuals, banks, and governments. If accounts become numerous, they cannot all be entered in one book and so are further divided into ledgers corresponding to groups of the alphabet, as A-F, G-M, and O-Z. Under the name of each customer, entry is made of all credits to his account from his deposit slips and all debits resulting from his checks.

The records of the departments are also transposed into accounts grouped according to the class of transactions. These accounts summarize the transactions of the bank and constitute the general ledger. Thus every bank has an individual bookkeeper who enters the separate dealings with customers, and a general bookkeeper who assembles the complete records of the bank.

A large bank maintains an auditor's department to verify records and to improve the systems of keeping books. Some departments of the bank are audited only at various times throughout the year, while others handling cash or securities are under continuous scrutiny. In addition to examining the records of the departments, the auditor's staff reconciles differences in the accounts of depositors and prepares the bank's reports to the government and to directors. It is essential to allow complete freedom of action to the auditor's department, so it is independent of the administrative officers of the bank and is accountable only to the board of directors.