If you have a multi-user version of QuickBooks, some situations cause QuickBooks to run slowly when two or more users are working in your company file.
For the best performance in multi-user mode, be sure to install QuickBooks on the same computer where the company file is located and set up that computer according to the recommended multi-user setup.
For tips on what you can do to improve slow performance, see these topics:
Where you install your company file
Tips for day-to-day operations
Tips for reports
Tips for printing
QuickBooks Enterprise Solutions offers enhanced multi-user performance.
About multi-user QuickBooks