When exporting reports as a PDF the driver now produces pages 12.75 x 18.03 inches. How do I change the default PDF export size to 8.5 x 11.0 inches?

Hello WCoaster, 

Thanks for connecting with us here. QuickBooks is designed to help you streamline your work using the powerful accounting features in the program. 

To get started, I recommend checking the report orientation as the Portrait mode has different dimensions compared to Landscape mode. Both of the orientations provide different dimension to the reports you export in QuickBooks. Another variable to take note of is the PDF producer and PDF version you're using. You can check this when you open the report in question > click on the Printer option ️> on the PDF screen click on the three dots to the right > select Document properties > here you'll be able to see more info pertaining to saving the report as a PDF. 

Let me know if you have other questions. I'm here to help steer you in the right direction.