Hi there PatAnd,
Making sure that your invoices are correctly accounted for is an important part of managing your sales. QuickBooks Online is a great tool to help your keep track of the money owed to you by your customers. I can provide some insight.
The feature to automatically add late fees to invoices isn't available in the Canadian version of QuickBooks Online. I can see how this feature would be something that can help you get paid faster. If you would want to see this possibly added to QuickBooks Online, I recommend you leave feedback by clicking the Gear Icon, then Feedback. Comments made in this section are considered when the developers design new features for QuickBooks Online.
If you have any more questions, feel free to reach out here.
