.QBX    Export file of Accountant’s Copy
You create this file to send your company file to your accountant.  To make an Accountant’s copy file, go to
•    File > Create Copy > choose Accountant’s Copy; or
•    File > Accountant’s Copy > Clients Activities > Save File.
You and your accountant then have to set the “dividing date” – the date that divide the transactions you can (& can’t) change and the transactions your accountant can (&can’t) change, as explained in the screenshot below:

 

QB File Types 1


 
.QBA    Converted .QBX file
QuickBooks creates this file when your accountant receives the .QBX file from you and opens it.  Your accountant must go to File > Open >Open an Accountant’s Copy Transfer File.

.QBY    Import file of Accountant’s Copy
You import this file from your accountant after changes are made.  To do this, go to File > Accountant’s Copy > Client Activities > Import Accountant Changes from Web or Import Accountant Changes from file.