# Quick Methods to Troubleshoot QuickBooks Error H303
**QuickBooks error H303** is one of the H-series errors that occur when switching to multi-user mode. This error prevents you from hosting your company file on the multi-user network. It represents something blocking your multi-user connection to your server.

Error code H303 appears on your screen with an error message on your screen that reads, ‘This company file is on another computer, and QuickBooks needs some help connecting.’ To learn more about this error and ways to troubleshoot, go through this comprehensive guide till the end. Also, be sure to follow each stepwise solution carefully.
If you are unable to follow this guide and are looking for some quick help, we suggest you connect with the team of QB experts on **855-955-1942** . Our team of experts is available to consult you with the best
## What Causes Error Code H303 in QuickBook?
Multiple reasons can be responsible for error code H303 when switching to multi-user mode; read these pointers to get familiar with them.

The Windows firewall settings are configured incorrectly.
QuickBooks Database services are not running on your computer, which triggers error code H303.
The multi-user mode on your server computer might be switched off.

**You are facing [QuickBooks Error Code 15240 when you are trying to QB update](https://dataservicesolutions.com/blog/advanced-troubleshooting-methods-quickbooks-error-15240/)**
## Top Resolution to Fix Multi-User Mode Error H303 in QB
Below are the top resolutions you should follow to get rid of error code H303 and host your company file in a multi-user connection without any issues.
**Note: Before moving to the troubleshooting solutions, make sure the multi-mode is switched ON on your server computer and OFF on your workstations.**
### Solution 1: Make Sure QuickBooks Services are Running on Your Server Computer

The QuickBooks Database Server Manager services help users host the company file on a multi-user network. Not running these services can interrupt the hosting and cause **[QuickBooks error code H303](https://dataservicesolutions.com/blog/fix-QuickBooks-error-h303/).**
* Go to your server computer and open the Windows Start menu.
* Type ‘Run’ in the search bar and click ‘Enter.’
* Type ‘services.msc’ in the ‘Run’ prompt, then press ‘Enter.’
* Look for the ‘QuickBooksDBXX’ on the list and double-click to launch it.
* Choose the ‘Startup Type’ as ‘Automatic.’
* Now, check the status of this service. It should be ‘Running’ or ‘Started.’ If it’s not running or started, click ‘Start.’
### Solution 2: Reconfigure Your Firewall Connection Settings
Incorrect Windows firewall settings can block QuickBooks files, which further prevents multi-user connections. Follow the below steps to reconfigure these settings.
* Open the Windows ‘Start’ menu by tapping the Windows icon key on the keyboard.
* In the search box, type ‘Windows Firewall’ and open it.
* Once done, go to ‘Advanced Settings’ and then right-click on ‘Inbound Rules.’
* Select the rule type as ‘New Rule.’
* Choose the ‘Port’ option and then click ‘Next.’
* Select the ‘TCP’ option and then choose the specific local ports field. Now, you must enter the QuickBooks version's specific port number.
-QuickBooks Desktop 2020 and later: 8019, XXXXX.
-QuickBooks Desktop 2019: 8019, XXXXX.
-QuickBooks Desktop 2018: 8019, 56728, 55378-55382.
-QuickBooks Desktop 2017: 8019, 56727, 55373-55377.
* Once done, click ‘Next’ and then choose ‘Allow the Connection.’
* Select ‘Next’ and be sure that all the profiles are marked. Then click ‘Next’ again.
* Finally, create this rule and name it as ‘QBPorts(year).’
* Once done, click ‘Finish’ and then try again to host your company file in a multi-user network.
The solutions mentioned above are all you need to follow to troubleshoot **QuickBooks error H303**. In case these solutions aren’t helpful for you or you require some professional help, **dial 855-955-1942** to connect with the QB expert and let them handle this task on your behalf.