What online store doesn't allow you to use different shipping and billing addresses when ordering items? AT&T's! Just about every online store nowadays accommodates this, which tells me that AT&T is trying really hard to mess up their customer's experience. This stinks for me, because we use PayTrust, so unless I want my shiny new phone to go to South Dakota, I have to use a different address. Calling support reveals that they have no way to order the iPhone period, much less to a different address.
When I first ran into this over two years ago with a Windows phone, there was no explanation on the site. Now, two years later, developers have thoughtfully addressed this issue with a bright red box with a change address link. If you follow the link to temporarily change your one and only (calling it a "billing address" would imply some other sort of address were possible) address, then go through the order process, you find at the last step that it's not immediately updated! Add to this all-around quirky UI and it's all enough to make you wonder how they ever made it beyond rotary phones.