Believe it or not, computers can make mistakes sometimes. We live in an age where data entry for bookkeeping is getting faster and faster via downloading or importing transactions. When the financial institutions communicate with QuickBooks a lot of information is exchanged and errors do occur. This is why the reconciliation step is so important. Every so often we will review a set of books and the credit card accounts are not reconciled. 'Why would they be off, I downloaded all the transactions' is the response we get when we point out the credit card balance is completely wrong. This is when we always have to tell the client that downloading is not reconciling. In addition to reconciling each time you download data you should look over renaming rules too.