Do both boxes get selected for local CO state taxes, when an employee works in Denver?

Yes, you'll need to select both local tax boxes for Colorado when your employee works in Denver. Let's get through the details below, Nick.

In Colorado, employees working within the city limits of Denver must select both the local tax boxes for Denver and Denver County when filling out their payroll forms. This requirement stems from the Occupational Privilege Taxes (OPT) that Denver imposes on individuals earning income within the city. It is essential to ensure that the local Employer Identification Number (EIN) and deposit schedule are correctly set up in the payroll system to ensure accurate tax processing.

For detailed information about setting up local taxes, you can visit this article: Set up local taxes in payroll.

Also, you can run a payroll report if you want to view your local tax liability amounts.

I'll keep this thread open if you have other concerns or questions regarding setting up local taxes in QuickBooks Online. The Community has your back always.