How to Fix The QuickBooks Error H303?

QuickBooks Error H303 is a multi-user mode configuration error that occurs when QuickBooks Desktop cannot establish a connection with a company file located on another computer within a shared network. The issue typically results from restricted server communication, misconfigured firewall settings, or improper hosting setup. This disruption prevents synchronization between the database server and connected workstations, preventing users from accessing shared financial data.

This article outlines the technical attributes of QuickBooks Error H303, identifies its root causes, and presents verified troubleshooting procedures based on Intuit’s diagnostic standards. It also includes preventive configuration practices, such as managing firewall permissions and using the QuickBooks Database Server Manager to maintain consistent and secure multi-user functionality.

What is Error Code H303 in QuickBooks?

QuickBooks Error H303 comes under the H series of QuickBooks errors, related to multi-user mode. Error H303 occurs when QuickBooks Desktop is unable to access a company file on another computer, as they need additional configuration settings to enable them to do so. Hence, Error Code H303 pops up when there is a lack of such settings.

Possible Reasons Behind QuickBooks Error H303

QuickBooks Error H303 occurs when the multi-user mode fails to function correctly, restricting the desktop application from establishing a stable connection with the company file stored on a network server.

1. The Network Data file is corrupted/ damaged.
2. The firewall is blocking server and workstation communication.
3. Lack of proper additional configuration of hosting settings.
4. An issue with the computer network.
5. QuickBooks is not acquiring files properly from the server, because it can’t get IP addresses of company files.
6. Database Server Manager Services and QBCF Monitor fail to start.

Troubleshooting QuickBooks Error H303 – Verified Solutions

The following verified solutions resolve QuickBooks Error H303 by correcting network settings, firewall restrictions, and hosting configurations to restore seamless multi-user connectivity and ensure stable communication between the server and connected workstations.

Solution 1: Using The File Doctor Tool

1. Close the QuickBooks.
2. Visit the official website of Intuit. Here, download and install the latest version of QB Tool Hub.
3. At last, open the QB Tool Hub.
4. Go to company file issues–> Run QuickBooks File Doctor.
5. Here, go to the drop-down list and choose the company file.
6. Continue with the process and click next.
7. Wait for the scan to complete. After that, the application will repair all damaged files on its own.

Finally, check back the issue of QuickBooks Error H303 by accessing the file again after the end of the process. Hopefully, it will fix the issue.

Solution 2: Change the Company File Location

By default, QB saves the company file to C:\Users\Public\Documents\Intuit\QuickBooks\yourcompanyfile.qbw. To change the location where your company file is stored, do the following:

1. Go to its current location.
2. Hit right-click on the file and choose Copy.
3. Navigate to the new place where you want to save it, right-click to an open area, and click Paste.
4. Open your QuickBooks software.
5. Select Open or restore an existing company, and Open a company file.
6. Click Next to proceed. A new window will display.
7. In the window, move to the new location of your copied company file.
8. Choose the file to highlight it and click Open. 
9. Your company file will start appearing on the login screen.

By opening the company file again, you will get to know if the error persists or not. Hopefully, it will resolve the QuickBooks Error H303.

Solution 3: Changing The Firewall Settings

1. Firstly, go to start–> control panel–> Firewall Settings.
2. On the left side, click this option: Allow a program through the firewall.
3. After that, go to add programs option to put QuickBooks in the exception list.

At last, save the settings and restart the system to check whether the changes have resolved the error or not. If this method wasn’t effective, check out the option mentioned below.

Solution 4: Check The Hosting Settings

1. Open the QuickBooks Program across all the workstations and servers.
2. After that, follow this path: File–> Utilities–> Stop Hosting Multi-User Configuration.
3. However, we have to restart the hosting. Hence, go to the File menu again to do the same.
4. On the file menu, follow this path: Utilities–>Host Multi-User Configuration.

Now that you have changed the hosting settings through the host multi user access option, reboot the system. After that, open the application again to verify if the QuickBooks Error H303 is resolved or not.

Additional Tip : Set-Up Database Server Manager to Avoid QuickBooks Error Code H303

Here is how you can go to the Database Server manager:

Go to the computer where the company file exists. After that, go to the start menu–> open QuickBooks Database Server Manager. This DSM will scan all the files. Also, it will restore your connection. These are the two methods that can help you setup the Database Server Manager:

1. Using the Full Program: Here, the user needs to install a complete version of QuickBooks. It includes both DSM and the QuickBooks desktop software.

2. Using the server option: Here, you are needed to install the DSM only on the server system.

Conclusion!

QuickBooks Error H303 is a network configuration issue that disrupts access to company files in multi-user mode. Running QuickBooks File Doctor, adjusting firewall settings, and configuring hosting options can resolve the error and restore multi-user functionality.

To prevent future occurrences, users should keep QuickBooks software updated, maintain proper network configurations, and ensure the Database Server Manager is correctly set up. These measures will help sustain smooth and uninterrupted multi-user performance across all connected workstations.

Contact our eBetterBooks Support number +1-802-778-9005 for immediate support if the error persists or additional assistance is needed even after applying these solutions.

FAQs!

1. What are the absolute minimum Windows permissions required on the shared folder to prevent multi-user errors?

This is critical for preventing permissions-related H-series errors. The User Account running the QuickBooks Database Server Manager (QBDSM) must have the following NTFS security permissions for the folder containing the .QBW file:

• Full Control (Recommended for the QBDataServiceUserXX account and the Administrator running the installation).
• Modify
• Read & Execute
• List Folder Contents
• Read
• Write

If the QBDSM service doesn’t have “Full Control,” it can’t correctly create or update the crucial Network Data (.ND) file, leading directly to connection errors like H303.

2. How do I manually check if the QuickBooks Database Server Manager service is actually running on the host computer?

You shouldn’t just assume the service is running; you need to verify its status:

1. Press Windows Key + R to open the Run box.
2. Type services.msc and press Enter.
3. In the Services window, locate the service named QuickBooksDBXX (where XX corresponds to your QuickBooks year, e.g., QuickBooksDB34 for 2024).
4. Check the Status column. It should read “Running.”
5. Check the Startup Type column. It should be set to “Automatic.”

If the status is blank, right-click the service and select Start. This is a quick way to diagnose a basic H-series error cause.

3. Why did my firewall exception break after I installed a QuickBooks update?

This is a common issue with firewalls and QuickBooks’ dynamic ports. When QuickBooks updates to a new year (e.g., from QB 2024 to QB 2025), or even sometimes after a major patch, the Database Server Manager may assign a new dynamic port number.

Your firewall exceptions were set for the old port. The solution is to:

1. Open the QuickBooks Database Server Manager on the server.
2. Go to the Port Monitor tab.
3. Note the new port number displayed.
4. Update your Windows Firewall (or third-party firewall) to explicitly allow inbound/outbound communication through this new port.

4. What is the expert recommendation for the ideal location to store the company file (.QBW)?

The ideal location must balance accessibility and security. We recommend storing the .QBW file in a dedicated, non-root folder on the local hard drive (C: or D:) of the physical server or host computer that is only running the Database Server Manager.

Never store the .QBW file in:

• A cloud sync folder (like OneDrive or Dropbox).
• A mapped network drive (use the UNC path instead).
• A flash drive or external/removable media.

The optimal folder path should look like: C:\Users\Public\Documents\Intuit\QuickBooks\Company Files.

5. Should I use a mapped network drive or the UNC path to connect a workstation to the shared file?

As experts, we strongly recommend using the UNC path (Universal Naming Convention) over a mapped network drive to connect workstations.

• Mapped Drive (e.g., Q:\Data\File.QBW): This relies on the workstation’s local drive mapping, which can break easily due to Windows login or network errors.
• UNC Path (e.g., \ServerName\SharedFolderName\File.QBW): This is a direct, robust path that uses the server’s network name, bypassing local drive mapping issues and providing a more stable connection for the multi-user database service.

6. What is the correct way to shut down a server running QuickBooks multi-user mode?

To prevent file header damage and multi-user errors, the server should be shut down gracefully:

1. Verify All Users are Logged Out: Confirm that every user has completely closed QuickBooks Desktop on their workstation.
2. Stop Hosting (Optional but Recommended): On the server, go to File >Utilities > Stop Hosting Multi-User Access. This formally closes the database connection.
3. Shut Down: Proceed with the standard Windows shutdown.

This sequence ensures the database service (QuickBooksDBXX) cleanly releases control of the .QBW and .TLG files, mitigating the risk of corruption upon next startup.

Disclaimer: The information outlined above for “How to Fix The QuickBooks Error H303?” is applicable to all supported versions, including QuickBooks Desktop Pro, Premier, Accountant, and Enterprise. It is designed to work with operating systems such as Windows 7, 10, and 11, as well as macOS.