How to auto populate the Billing Address fields of the Payment Form

Also, is there any way to have a check box to populate the billing address fields with the address fields I have on the first page of my form?

I was experimenting this to autopopulate the address field to Billing address by placing the condition and it worked for me with a simple condition. It seems this feature is added recently. I've cloned your JotForm to my account and placed a checkbox as Billing address below the address field from Step 1. Then a condition has been set to fill if the checkbox is checked to update the address field to the payment field.

Please see the following screenshot that can help you in setting up the condition for this case.

You can also check the demo JotForm of your clone here.

http://form.jotformpro.com/form/50157349225959?

If you want, you may clone this JotForm to your account and make necessary modifications.

Hope this information helps. Please let us know if you need further assistance in this regard. We will be happy to help.

Thank you!!