Hello there, greg21.
I'm here to help you.
QuickBooks Online for Canada doesn't have the option to set up an email reminder for payroll due dates. You're right, this option is currently offered only for the US version.
As a workaround, you can look for supported apps to help send email reminders. We a lot of apps that you can try. You can search it in the Apps tab.
No worries. I'll surely forward this to our developers to let them know that this is something that you need.
For other concerns, please let me know. Have a great day!
