You can transfer transactions from one QuickBooks company file to another using Zed Axis. First step in the process is to select the transactions that you would like to transfer using the export module and filter for either since the last export, a date or reference number range and save the transactions to an Excel spreadsheet. Then connecting to the destination file you can import those transactions into QuickBooks using the import module. You even have the option to modify the transactions during the transfer as well as only bringing across the fields that you need.
Watch a demonstration of the process
You can download and improt the following basic maps for transfers of the following transaction types:
Article ID: 165, Created On: 11/15/2011, Modified: 11/23/2011