Is there a way to stop pdf preview on invoices?

Thank you for posting, @Anonymous.

After clicking Save and Send button when creating invoice, QuickBooks Online (QBO) automatically shows a preview of your invoice. It's in a PDF form so you can easily save a copy of it on your computer. 

As of now, there isn't a way to disable the PDF Preview when sending invoice. However, if you don't want your customers to receive an email of a PDF copy of their invoice, you can change the Online Delivery options.

Here's how:

1. Go to the Gear icon.
2. Select Account and Settings under Your Company.
3. Select Sales under the Account and Settings window.
4. Click the Online Delivery pencil icon.
5. You unchecked the box beside PDF Attached and select an email options for invoices under Additional email options for invoices.
6. Click Save.
7. Click Done.

You may check this article for additional reference: Email sales forms directly to your customers from QuickBooks Online.

I want to ensure customers like you are having the best possible experience while working with QuickBooks. If you think the option of removing/stopping the PDF Preview on invoices is what you need for your business, I suggest sending this idea straight to our product engineers for future updates.

To send you product feedback/suggestions:

1. Go to the Gear icon.
2. Select Feedback.

Feel free to add a comment below if you have any other invoices concerns. We're always here to help!