How do I enter a bill with 8% provincial sales tax, when that is not one of the options?

Hi there, 

It's good to have you reach out again. I'll help you with the sales tax on your bill.

Based on your description, it seems like you'd need to add a new tax rate that's only 8%. If that's the case, QuickBooks Online makes it easy to do that and I'll show you how. There's a great article which explains  how to add a new tax rate. I'll attach the link below:

https://quickbooks.intuit.com/community/Sales-tax/How-to-set-up-a-new-sales-tax-code/m-p/261929

I encourage you to got through the steps and if you get stuck, don't hesitate to reach out. :)