The ability to attach a PDF of your filing confirmation to HST tax payment in QuickBooks Online is currently unavailable, Mike.
We recognize how this option can help you seamlessly track your HST filing and payment record. Therefore, I recommend sending feedback directly to our product development team. Considering how it enhances your experience when managing tax liabilities, they might be incorporated into future product updates.
Here's how:
- Click on the Gear icon.
- Choose Feedback under Your Company.
- Share your product improvement ideas.
- Select Next to submit.

Whenever you need to see previous payments, proceed to the Payments tab in the Sales Tax center. Review each of the details by clicking View from the Action column. Here's a screenshot for your reference:

We're always a message away if you need further assistance handling sales tax returns and payments in QuickBooks Online. Ask any questions in the comment below, and we'll respond with all the necessary information to address them as soon as possible.