Fix QuickBooks Error H303 or H505: Hosting Configuration Error
- jakkibhasker
- Jan 23
- 4 min read

QuickBooks Error H303 or H505 occurs when QuickBooks Desktop is unable to establish a connection with the company file located on another computer or server. These errors are part of the H-series errors, which are directly related to multi-user mode and hosting configuration issues.
When these errors appear, users are blocked from accessing the company file in multi-user mode, disrupting collaboration, accounting workflows, and daily operations. This guide explains the causes, symptoms, and step-by-step solutions to fix QuickBooks Error H303 and H505 effectively.
What Is QuickBooks Error H303?
QuickBooks Error H303 indicates that QuickBooks cannot communicate with the server hosting the company file. This usually happens when the workstation cannot reach the server due to incorrect hosting settings or blocked network ports.
Common Message:
“Error H303: This company file is on another computer, and QuickBooks needs some help connecting.”
What Is QuickBooks Error H505?
QuickBooks Error H505 occurs when QuickBooks detects that the company file is hosted on a different system but cannot establish a secure connection to that server.
Common Message:
“Error H505: QuickBooks cannot access the company file on the server.”
Both errors point to network misconfiguration, hosting conflicts, or firewall restrictions.
Difference Between Error H303 and H505
Error Code | Primary Cause |
H303 | Workstation cannot communicate with hosting server |
H505 | Server hosting is unreachable or misconfigured |
Despite the difference, both errors are fixed using similar troubleshooting steps.
Common Causes of QuickBooks Error H303 or H505
QuickBooks Error H303 and H505 can occur due to one or more of the following reasons:
Incorrect hosting configuration
QuickBooks Database Server Manager not running
Firewall or antivirus blocking QuickBooks ports
Damaged or missing .ND (Network Descriptor) files
DNS or network connectivity issues
Multiple systems set to host the company file
Incorrect QuickBooks services settings
Company file stored in an inaccessible location
Identifying the root cause helps apply the correct fix quickly.
Symptoms of QuickBooks Error H303 or H505
Unable to switch to multi-user mode
Company file opens only in single-user mode
Frequent QuickBooks freezing or crashing
Error appears when opening company file from workstation
Slow network performance
Important Steps Before Troubleshooting
Before you start fixing the error, complete these preparatory steps:
Close QuickBooks on all computers
Ensure only one server hosts the company file
Log in as Windows Administrator
Verify stable network connectivity
Temporarily disable antivirus/firewall
Solution 1: Verify Hosting Settings on All Computers
Incorrect hosting configuration is the most common cause of Error H303 or H505.
Steps:
Open QuickBooks on each workstation
Go to File > Utilities
If you see Stop Hosting Multi-User Access, click it
Do this on all workstations
On the server computer, ensure Host Multi-User Access is enabled
Only the server should host the company file.
Solution 2: Use QuickBooks Tool Hub (Recommended)
QuickBooks Tool Hub includes tools specifically designed to fix H-series errors.
Steps:
Download and install QuickBooks Tool Hub
Open Tool Hub
Select Network Issues
Run QuickBooks Database Server Manager
Scan the folder containing the company file
Restart QuickBooks on all systems
This ensures proper network configuration and file accessibility.
Solution 3: Check QuickBooks Services on the Server
Certain QuickBooks services must be running on the server.
Steps:
Press Windows + R, type services.msc
Locate:
QuickBooksDBXX
QBCFMonitorService
Ensure Startup Type is Automatic
Start the services if stopped
Restart QuickBooks after making changes.
Solution 4: Rename Network Descriptor (.ND) Files
Damaged .ND files can prevent QuickBooks from locating the company file.
Steps:
Open the company file folder
Locate the file with .ND extension
Right-click and rename it to .old
Open QuickBooks Database Server Manager
Scan the company file folder again
New .ND files will be created automatically.
Solution 5: Configure Firewall Settings
Firewall restrictions often block QuickBooks communication.
Steps:
Open Windows Firewall
Allow inbound and outbound rules for QuickBooks
Open ports required by your QuickBooks version
Add QuickBooks programs as exceptions
If you use third-party antivirus software, apply similar exclusions.
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Solution 6: Verify DNS and Network Connectivity
Network instability can cause Error H303 or H505.
Steps:
Open Command Prompt
Type:
ping servername
Ensure there is no packet loss
Verify all computers are on the same network
Resolve any network issues before proceeding.
Solution 7: Move Company File to the Server
The company file must be stored on the server, not on a workstation.
Steps:
Create a dedicated folder on the server
Move the company file (.QBW) to that folder
Share the folder with full permissions
Open the file from the server location
Solution 8: Turn Off Hosting on Workstations
Multiple hosting systems can confuse QuickBooks.
Steps:
Open QuickBooks on each workstation
Go to File > Utilities
Select Stop Hosting Multi-User Access
Restart QuickBooks
Solution 9: Open Company File Using UNC Path
Mapped drives can sometimes cause connectivity issues.
Steps:
Open QuickBooks
Click Open or Restore Company
Browse using:
\\ServerName\SharedFolder\CompanyFile.qbw
This creates a direct network connection.
How to Prevent QuickBooks Error H303 or H505
Host company files on a single dedicated server
Use QuickBooks Database Server Manager regularly
Keep QuickBooks updated
Maintain firewall and antivirus exceptions
Avoid opening company files over weak networks
Perform regular backups
Frequently Asked Questions (FAQs)
Are H303 and H505 serious errors?
They are network-related errors but can be fixed without data loss.
Can I fix H303 or H505 without IT support?
Yes, most users can resolve these errors using Tool Hub and proper hosting setup.
Do these errors affect data?
No, they block access but do not damage the company file itself.
Conclusion
QuickBooks Error H303 or H505 (Hosting Configuration Error) occurs when QuickBooks cannot communicate with the server hosting the company file. These errors are usually caused by incorrect hosting settings, firewall restrictions, or network configuration problems.
By following the step-by-step solutions in this guide—verifying hosting setup, using QuickBooks Tool Hub, configuring firewall rules, and ensuring proper network connectivity—you can restore multi-user access and keep QuickBooks running smoothly.


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