The posting date is the date upon which a transaction is actually recorded. For example, you might write a check on the 5th of the month and then mail it to a creditor. They might receive it on the 9th but not process it until the 10th. The check finally is processed by your local bank on the 11th and the funds are debited from your checking account. Although written on the 5th, the check’s posting date is the 11th.