If I accidently paid the Q3 quarterly TX Unemployment Tax too soon, how can I pay the remaining amount?

Hi there, @jenn23.

I'll help you pay the remaining amount of your taxes in QuickBooks Online (QBO) Payroll. 

Simply go to Payroll Tax Center and find the quarterly tax that you need to pay. Let me show you how:
 

1. Go to the Taxes menu and select Payroll Tax.
2. Click Pay Taxes.
3. Look for the TX Unemployement Tax and select Record payment.
4. Continue by clicking Record Payment.

Also, you can run payroll reports in QBO. You can them to view useful information about your business and employees. Just click this article to know more about these reports and how to access them: List of payroll reports available in QBO Payroll.

Don't hesitate to tag my name in the comment section below if you have other concerns or questions. I'm always ready to help. Have a great day and stay safe.