When Working in QuickBooks Pro or QuickBooks Premier, the following functions will not work unless you are in single-user mode:
- Backing up, condensing (Clean Up), converting, Data rebuild, restoring, or updating the company data file.
- Changing company information.
- Changing Company preferences, Including Closing Date.
- Importing or exporting data (with the exception of Online Banking which works just fine in multi-user, but only one person can work it at the time)
- Merging, deleting, or resorting list items such as names, vendors, and items.
- Changing income or Expense/COGS account from items.
- Signing up for a QuickBooks Payroll Service.
- Printing Form 1099-MISC.
- Mapping a network drive from within QuickBooks.
- Defining, creating, or modifying custom fields.
- Exporting QuickBooks to TurboTax.
- Accountant’s review activities. (The Accountant’s copy may be opened in multi-user Mode and then all applicable restrictions apply.)
- Performing Inventory Adjustments
- Change sales tax rates
However, with QuickBooks Enterprise, the following functions can be done with multi-user mode:
- Adjust inventory
- Edit or Delete list items
- Change sales tax rates
- Define custom fields
- Set a closing date
- Make deposits (multiple users can make deposits at the same time)
- Change any list sort order
It is difficult to find a definitely list from intuit that defines all the restrictions and limitations of Pro/Premier and Enterpise, but this list should be pretty good start.