Error -6073, -99003
File accessed in single-user mode on another workstation
Medium Severity
Fix Time: 10-15 minutes

Problem Overview

This error occurs when a QuickBooks company file is being accessed in single-user mode on one workstation while another user attempts to open the same file. QuickBooks prevents multiple users from accessing a file simultaneously when it's in single-user mode, which causes this conflict.

Common Symptoms

  • Unable to open the company file
  • "File in use" error message
  • QuickBooks becomes unresponsive
  • Error message mentioning single-user mode

Affected Components

  • QuickBooks Company File (.QBW)
  • Network File Sharing
  • User Access Permissions
  • Database Server Manager

Quick Resolution

  • Check for other users
  • Switch to multi-user mode
  • Restart database services
  • Clear temporary files

Step-by-Step Solution

1
Check for Other Users
Determine if any other user is currently accessing the QuickBooks company file. Contact team members to confirm if anyone has the file open.
Note: This is the most common cause. Often, a user has the file open without realizing it.
2
Close QuickBooks on All Workstations
Ask all users to completely close QuickBooks on their computers. Make sure to check the system tray for any running QuickBooks processes.
// Steps to properly close QuickBooks:
1. Save all work and close all company files
2. Go to File → Exit
3. Check system tray for QuickBooks icon
4. Right-click and select "Exit" if present
3
Verify File Access Mode
Open QuickBooks on the main workstation and verify that the company file is set to multi-user mode.
  1. Open QuickBooks (make sure you're the only user)
  2. Go to File menu
  3. Select Switch to Multi-user Mode
  4. Wait for the process to complete
  5. Confirm the mode change in the title bar
Warning: Do not attempt this while other users have the file open. This will cause data corruption.
4
Restart QuickBooks Database Server
If the error persists, restart the QuickBooks Database Server Manager to clear any file locks.
  1. Press Windows Key + R to open Run dialog
  2. Type services.msc and press Enter
  3. Locate QuickBooksDBXX (XX represents version)
  4. Right-click and select Restart
  5. Wait for the service to fully restart
5
Clear QuickBooks Cache
Clear temporary files and cache that might be causing the conflict.
  1. Close QuickBooks completely
  2. Press Windows Key + R
  3. Type %temp% and press Enter
  4. Delete all files in the Temp folder
  5. Empty Recycle Bin
  6. Restart your computer

Prevention Tips

User Management

Always use multi-user mode when multiple people need to access QuickBooks. Establish clear protocols for file access in your organization.

Regular Updates

Keep QuickBooks updated to the latest version. Updates often include fixes for common file access issues and improve stability.

Network Configuration

Ensure proper network permissions for the QBW file location. Use the QuickBooks Database Server Manager for networked installations.

Backup Strategy

Implement a regular backup schedule for your company file. This protects against data loss from file corruption issues.

Frequently Asked Questions

What causes QuickBooks Error -6073, -99003?

This error occurs when multiple users try to access a QuickBooks company file that is set to single-user mode. The file gets locked by the first user, preventing others from opening it.

Can this error cause data loss?

While the error itself doesn't cause data loss, improper handling (like force-closing QuickBooks) can lead to file corruption. Always follow the proper steps to resolve the issue.

How do I prevent this error from happening again?

Set your company file to multi-user mode if multiple people need access. Establish clear procedures for opening and closing the file, and ensure all users properly exit QuickBooks.

What if the error persists after following all steps?

If the error continues, there may be network permission issues or file corruption. Contact QuickBooks support or your IT administrator for further assistance.