Is there a way that I can put checkboxes on an invoice or quotation template, so that the total amount owing is based on what the customer selects from a list of options?

Welcome to the Intuit Community, ben117.

At the moment the feature you're looking is unavailable in the current set of features and offerings. QuickBooks Online has the Custom form style feature that allows you to edit and customise your sales forms.

If you want to show the total amount owed by the customer, you can create and send a customer statement in QBO. However, just a heads up that the customer statement will show the running balance as of date format.

To create a customer statements:

1. Click on the Sales tab, and the click Customers tab.
2. Tick the box for the customer/s you want to make a statement.
3. Click the drop down arrow beside the Batch actions, and then click Create statements.
4. Select the Statement type from the drop down option.
5. Choose the date range for the statement.
6. Review the email address.
7. Click on Print or Preview or Save and send.

Here's a few handy link for your reference:

• Customise Invoices, Quotes and Sales receipts in QuickBooks Online
• Create and Send Customer Statements in QuickBooks Online

Please reach out again if you have any other questions.