After setting up a new employee I am getting "Network error: Response not successful: Received status code 400" and shows additional information is needed?

Good day, @youngexplorerpre.

We have an ongoing investigation where some of our customers received the same error message when editing the W-4 information. Our product engineers are now prioritizing this so you can get back to your business as soon as possible.

I recommend giving our Customer Care Team a call to add your account details to the list of affected users. This way, you'll receive an update as soon as a fix becomes available.

1. Click the Help menu in the upper-right hand corner and click Talk to a human.
2. Type in "Talk to a human", then press Enter.
3. Look for I still need a human and click on it.
4. Select Get help from a human.
5. Choose between Chat with us, Schedule an appointment, or Have us call you.

 
Please check out our support hours to ensure that we address your concerns on time.

Additionally, there are new changes to the Federal W-4. If you wish to know more about this, I'd recommend checking out this article: What’s changing with the Federal W-4?. It also answers the most frequently asked questions about it and guides you on how to print one for your employee.

In the meantime, I'm also adding this article to further guide you in managing your employees and payroll account in QBO: QuickBooks Help Articles. It includes topics about editing payroll, its benefits, and subscription management, to name a few. You can click the + More topics button to view other selections.

Please keep me posted on how it goes. If you have other concerns about adding employee's W-4 information in QBO, I'm just around to help. Take care always.