Hi there, @gcombe.
Let me assist you on how to remove your employee's from your QuickBooks Online account.
If you're using QuickBooks Online Standard Payroll, you can mark your employee as a leaver. Leaver is an employee that is no longer in your business and is not visible when you are creating payslips.
You can follow these steps on how to mark your employee as a leaver:
5. Select Done to dismiss the note that their P45 will be available at the end of the final payroll.
However, if you're using QuickBooks Online Advanced Payroll, you can terminate your employee by following these steps:
I've also added an article to help you manage your employee's status in your QuickBooks Online Standard Payroll.
Please know that I'm always around here in the Community to help. Take care, and have a good day.