I have had the exact same issue since migrating from QuickBooks desktop. It is a MISERABLE failure on Intuit's part that their importing algorithms mess up the addresses so badly. It is also a miserable failure that QBO doesn't allow the options of saving an edited billing address the way QuickBooks Desktop does. Desktop asks "You have changed the billing address. Do you want to save this new information for next time?" or something like that. Intuit NEEDS to really fix the migration importing algorithms or allow a lot more customization of that process, AND need to take a closer look at Desktop features that are missing in QBO. I will likely be canceling my online subscription and going back to desktop very soon.