When a business has been in operation for many years and has continued to use the same Quickbooks file, the size can get extremely large. Sometimes the data cannot be upgraded into the new version at all because of size. In fact, Intuit recommends that users condense files, otherwise, why would such an option even exist within the software? It is to help the user manage the data in the most efficient way possible.
One last thing to be aware of when using Quickbooks in general, is that an audit trail does exist. An IRS agent can go back and look at every transaction, change, deletion or any activity that occurs within the file. While this does go away for the years in which the file has been condensed, it is still intact for years after that point.
This audit trail feature can be very useful to a business owner in that he/she keeps the administrative rights, and assigns usernames and passwords to others who enter any data into the file. This way, various users activity can be tracked, and it makes it easy to question why a certain transaction may have occurred, or been deleted. Sometimes these mistakes happen, and it is also a helpful feature to go back and see what the original transaction was before the change was made.