A check register is like a journal in which you record your checking account activity. It is also called a “check ledger” or “transaction register.” You can use it to track recent withdrawals and deposits you’ve made as well as recurring automatic transactions (e.g., online bill payments and direct deposits). By doing so, you’ll know how much money you actually have in your bank account at any time, and you can easily spot errors (or fraudulent activity) that you otherwise might overlook.