Condense or Cleanup Quickbooks. Quickbooks has a built-in utility that will reduce the file size of your Quickbooks data file. The Quickbooks condense operation condenses closed transactions into summary journal entries. If any list items are not used, they are deleted from QuickBooks.

 Here is the full intuit article :

https://quickbooks.intuit.com/community/Account-management/Use-the-Condense-Data-utility/m-p/203359

Hope so this will help you

Regards,

Adrian

QuickBooks Hosting expert - Apps4Rent