You should get a screen where you can check your address etc, before paying. Ebay bought this type of instant checkout in some time ago. There is no way to change it, believe me, I have tried. Some will tell you to untick automatic payments to Paypal, but that refers to Paying my eBay fees, which are paid automatically. You will find if you buy from other sites, you will be required to put in your Paypal password.
