If your company file is synced with Intuit online services using the Intuit Sync Manager, some file operations can force the Sync Manager to reupload your company file from scratch. This should be avoided whenever possible for 2 reasons:
Reuploading the company file can take up to several hours, depending on the size of the file and your internet connection. See the Help in the Intuit Sync Manager to estimate how long this will take for your file.
If your online service or application uses 2-way sync, (meaning changes you make in QuickBooks go to your online service and vice-versa), you'll lose changes you've made online that haven't yet synced to QuickBooks at the time the file is reuploaded. The QuickBooks data will overwrite any unsynced online data.
When the Intuit Sync Manager needs to reupload your file, sync will be disabled for that file and you'll be prompted by the Sync Manager to enable sync and reupload the file during the next sync attempt.
To avoid a reupload
To back up and restore a synced company file, follow these guidelines.
To move, copy, or rename a synced company file, use the instructions in the Intuit Sync Manager Help.
While updating a synced company file for a new version of QuickBooks, avoid choosing the option to reupload the company file if possible. (In a few situations that may be unavoidable.)