Is vacation acccrued on overtime and double overtime hours?

I've got the details you need about tracking vacation pay in QuickBooks Online Payroll (QBOP), @suesailor. 

Yes, the vacation pay will accrue on overtime and double overtime hours. However, we use the regular rate to calculate it. Just make sure to choose per hour worked as the Accrual Frequency for this policy. See the screenshot below for your visual reference. For more details, check out this article: Set Up And Track Time Off In Payroll. This link contains steps on how to set up time off, update your existing policy, and add paid or unpaid time off. 

Moreover, I'd suggest running the Vacation and Sick Leave report from the Reports menu. It provides you a summary of your employees' time off accrual and usage info, such as vacation pay. Just click the amount in the Current Vacation Available column to view the details. I've attached a screenshot below on how the report looks like in QBOP. 

I'll be right here to help if you need further assistance. Have a great rest of your weekend, @suesailor. 

Is there a way to not accrue PTO hours when an employee works overtime?

Hello there, MBXcel.

Yes, there is. QuickBooks allows you to not accrue PTO hours when your employee works overtime. We'll only have to uncheck the Paid Time Off option in our employee setup. Let me guide you further. Here's how:

1. From the left menu, click Workers.
2. Select the Employees tab and choose the name of the employee.
3. Click the pencil icon in the Pay section.
4. From the How much do you pay employee? section, click Edit.
5. In the You can also pay section, remove the check-mark for Paid time off.
6. Then, Done.
   

If you use the default hours, the system will use the default hours when running payroll. If you want to pay your employees different hourly rates, you can utilize the Add additional pay types option to add another hourly rate. You can check this for additional reference: Pay an employee different hourly rates.

I'd always want to help. If you have more questions about payroll or anything related to QuickBooks, don't hesitate to post them. Take care always.