The account balance is simply the amount of credit or debt existing in a given account on a given date (the report date). For a savings account, the account balance will be a positive amount. For a credit card account, the account balance will be stated in positive numbers, but will indicate the amount you owe (liability / debt) to your credit card company. Account balances may fluctuate daily from many causes, including new checks written, new charges accrued, finance charges, deposits, or refunds.
Thus, when reviewing paper statements which have been delivered through the mail, account holders should recognize that the printed account balance may vary significantly from the account balance on the day the statement is reviewed. Even if you check your accounts online, keep in mind that there is often a time lag (although not nearly as large as paper statements) in reporting current account balances. In order to make sure your numbers are correct, you should always reconcile your records with your statement or online reports. Errors do occur from time to time. Spend a few extra minutes at least once a week and always make sure that your records are kept up to date. Doing so can possibly save you money by preventing unauthorized charges, over the limit (credit card and credit line accounts) and overdraft fees (checking accounts).