Thanks for reaching out to the Community for support. I'm happy to provide some insight about connecting the payroll to the 401K account.
At this time, the ability to connect QB Payroll to the 401K account is currently not support yet. However, I can see how this would be beneficial for you and your business. If you'd like, I can submit a feedback request to our product development team, so this could be considered in a future update.
In the meantime, please let me know if you have additional questions or concerns. I'll be here every step of the way. Feel free to reach out to the Community at any time. Take care!