Reconciling the general ledger is an output control that can detect certain types of
transaction processing errors. For example, the total of all credit sales recorded by billing
should equal the total increases posted to the AR subsidiary accounts. A sales transaction that is entered in the journal but not posted to the customer’s account would be detected by an imbalance in the general ledger. The specific cause of an out-of-balance condition could not be determined at this point, but the error would be noted. Finding the error may require examining all the transactions processed during the period. This could be time consuming. For this reason, rather than summarizing an entire day’s transactions in a single batch, entities often group transactions into small batches of 50 to 100 items. This facilitates reconciling balances by isolating a problem to a specific batch.