I'm here to share some information on how billable paycheck works in QuickBooks.
Paychecks will be billable depending on a time activity as billable if there are expenses that are incurred by you on behalf of your client. You can unmark it if you're not billing or invoicing these expenses to your clients.
I also recommend reaching out to your payroll admin or an accountant to ensure that the paycheck is billable or not.
Furthermore, let me share this link to help you manage paychecks for an employee: Set up and create paychecks.
Additionally, you can visit these articles to learn more about the hourly rate of salaried employees and tracking payroll expenses: