QuickBooks error 15XXX series can be annoying for users while working on a QuickBooks desktop. Different error codes imply different root causes and shall be fixed using the troubleshooting steps as required. In this support article, we will talk about rising QuickBooks error 15240 while working on Payroll or updating QuickBooks desktop payroll service.

QuickBooks Error 15420 during Payroll Updates

Encountering errors while updating payroll on QuickBooks desktop can be frustrating for users. QuickBooks error 15420 is one of the error codes that is seen in the QuickBooks update window when getting payroll updates. In this comprehensive guide, we will delve into repairing QuickBooks error 15420 by performing intuitive troubleshooting steps.

Causes of QuickBooks Error 15420

Error code 15420 can be seen due to various reasons while updating QuickBooks payroll. Some of the major causes in our collection of events where users face QuickBooks error 15420 are:-

  1. Incorrectly mapped Shared Download drive
  2. Disabled QuickBooks File Copy Service (FCS)
  3. Digital signature verification failures
  4. Missing files or Damaged Windows components for payroll updates
  5. Damaged QuickBooks company file
  6. Firewall settings are blocking payroll updates
  7. Outdated QuickBooks desktop version

Setup Firewall Configuration Manually Before troubleshooting

Before performing troubleshooting steps you should configure your firewall manually to ensure that it is not the reason for QuickBooks error 15420.

Method 1 – Adding Firewall Port Exceptions for QuickBooks

If you have multiple versions of QuickBooks Desktop installed on the same computer, follow these steps for each version:

  1. Click on the Windows Start menu.
  2. Type “Windows Firewall” into the search box & open Windows Firewall.
  3. Choose Advanced Settings.
  4. Right-click on Inbound Rules (you’ll tackle Outbound Rules later) and select the New Rule option.
  5. Select Port and proceed to the next step.

Windows Firewall Advanced Settings: Rules and Specific Local Ports

QuickBooks Error 15420

Ensure that TCP is selected. In the Specific local ports field, input the required ports for your QuickBooks year version:

Note: QuickBooks Desktop 2019, 2020, 2021, 2022, 2023, & 2024 utilize dynamic ports assigned during installation for exclusive use.

Method 2 – Locating the Dynamic Port Number

  1. Launch the Windows Start menu.
  2. Look for “QuickBooks Database Server Manager” and open it.
  3. Navigate to the Port Monitor tab.
  4. Identify your QuickBooks desktop version and note the Port Number provided.

Should you opt to change the assigned port number, select Renew. Then, head to the Scan Folders tab and choose Scan Now to reset firewall permissions. Remember, port renewal is applicable only for Desktop 2019 and subsequent versions (till 2024).

Once you’ve entered the correct port number, proceed to the next step. Click on Allow the Connection and proceed. If prompted, ensure all profiles are selected.

Then, click on continue. Name the rule appropriately, such as “QBPorts(year),” and click Finish. Repeat the above steps to create outbound rules, ensuring to select Outbound Rules.

Afterward, switch QuickBooks Desktop to QuickBooks multi-user mode. Alternatively, access QuickBooks over your network from a host computer.

Creating Windows Firewall Exceptions for QuickBooks Programs

QuickBooks relies on executable files (.exe) for various functions. Follow these steps to create exceptions for each executable listed:

  1. Open the Windows Start menu.
  2. Search for “Windows Firewall” and open it.
  3. Select Advanced Settings.
  4. Right-click on Inbound Rules (Outbound Rules will be addressed later) and select New Rule.
  5. Choose a Program and proceed.

Ensure you’ve selected This Program Path, then click Browse. Locate and select an executable file from the provided table. Continue. Select Allow the Connection and proceed. If prompted, ensure all profiles are selected. Then, continue.

Name the rule appropriately, such as “QBFirewallException(name.exe).” Repeat the above steps to create outbound rules, ensuring to select Outbound Rules.

Upon completion, restart your computer for the changes to take effect. Once restarted, reopen QuickBooks. If issues persist, proceed to the next section regarding antivirus settings.

Checking Antivirus or Firewall Settings

Adding QuickBooks Port Exceptions to Your Antivirus or Firewall

How to Repair QuickBooks Error 15420

Perform these foolproof troubleshooting methods to fix QuickBooks error 15420. Do not forget to make a backup of your QuickBooks company file before trying the below-mentioned solutions.

QuickBooks Error 15420
Call our toll-free support or chat with an advisor for Quick Error Support

Run QuickBooks as an Administrator

Run QuickBooks desktop as an admin and then update your QuickBooks desktop & Payroll:-

Use QuickBooks Tool Hub

Download and Install the QuickBooks tool hub and use the Quick Fix My Program feature to fix QuickBooks error 15420.

Launch Quick Fix My Program to check

After you have downloaded and installed the QuickBooks tool hub, open the application and in the launchpad follow the steps below:-

QuickBooks Error 15420
Quick Fix My Program Feature in QuickBooks tool hub

Now, Go to the QuickBooks desktop update window to start updating QuickBooks desktop and payroll again. If the issue persists, try the below steps for troubleshooting QuickBooks error 15420.

Delete Component File

QuickBooks payroll error 15420

Check if you are still getting QuickBooks Error 15420 in the update window for payroll. If the error persists, move on to the next solution.

Install Digital Signature Certificate

quickbooks error 15420

Repair QuickBooks Desktop

Download and Run the QuickBooks Install Diagnostic tool within the QuickBooks tool hub. Follow the instructions on how to do it:-

quickbooks install diagnostic tool
quickbooks install diagnostic tool download
use quickbooks install diagnostic tool

Uninstall and Install QuickBooks

Re-install your QuickBooks desktop to fix QuickBooks error 15420. Perform the steps below:-

Contact QuickBooks Error Support

If the above-provided troubleshooting steps for QuickBooks error 15420 do not resolve the error. Reach out to the QuickBooks error support team for prompt assistance. Our QuickBooks desktop support team is fully equipped with advanced tools and information to repair any QuickBooks error swiftly.


When does QuickBooks Error 15420 occur?

QuickBooks error 15420 occurs while downloading payroll updates for the QuickBooks desktop.

How to fix Error 15420 in QuickBooks desktop?

Download and install the QuickBooks tool hub and run Quick Fix My Program to fix error 15420 easily.

Where to download and find Quick Fix My Program to repair error 15420?

Navigate to Program problems in the QuickBooks tool hub launchpad and you will see the feature Quick Fix My Program there.