Per AT&T, a Post Office Box cannot be used in place of a street address, in compliance with the Mobile Telecommunications Sourcing Act, which I believe is also connected to USA-PATRIOT requirements. (Thanks to amberdine for the link.)
However, the MTSA does not require that the payment mechanism (ie, credit card billing address) be a street address, only that a street address must be associated with the account. I am an AT&T iPhone user who gets his bills at a PO Box, and AT&T has my street address on file as part of the account. I have paid that iPhone bill on occasion in the past with this selfsame credit card without difficulty.
The issue with the iPad 3G data plans is AT&T provides no mechanism for gathering the street address in the event that the billing address is a PO Box. My completely uneducated guess was this was done to streamline the registration process, with fewer click-throughs and screens to fill in. But there's no legal requirement in play with respect to the credit card billing. It's a business decision on AT&T's part to lock out PO Box users by not allowing street addresses to be input as a secondary address.
Several people suggested I use my debit card. Problem there is it flows through the same PO Box as every other financial instrument I have. AT&T provides no alternate billing mechanisms such as ACH or PayPal, so I can't pursue that. The only possibility is for me to call my credit card company, change my account information, wait for that to propagate to the merchant account databases, then rerun the data plan sign up.
No other vendor has ever required me to go to so much trouble to purchase something from them. As Apple has granted AT&T exclusive status here, I have no choices. Neither do the tens or hundreds of thousands of other iPad users who prefer their PO Box address for any number of reasons.
To address a couple of other questions that came up, I use the PO Box because when I'm not on chemo I'm gone from home as much as half the month or more. I far prefer my mail safely locked up at the post office to sitting in my curbside mailbox where any passing meth head can rifle through it. This is a normal thing people do, and it's frankly better financial security. I'm not some kind of weirdo, and I'm certainly not trying to conceal my street address from my creditors and vendors. I'm happy to provide it on request. AT&T simply doesn't give me that option on the iPad 3G data plan.
Second, this isn't really a fraud issue as some have suggested. As it happens, I have quite a bit of familiarity with transaction processing and fraud management through my Day Jobbe. (That's why, for example, the zip codes have to match up.) AT&T already has my street address through my iPhone account. Even if they didn't, I'd be happy to provide it through my iPad account if they would let me. This is AT&T taking a nonstandard approach to credit card processing that locks me and thousands of others out.
I'm not going to work this any further until I get my iPad hardware issues resolved. I have a Genius Bar appointment tomorrow which may help, but I strongly suspect I have a lemon on my hands. However, I plan to file a complaint against AT&T and Apple with both my credit card issuer and with Visa, and possibly Oregon's consumer protection office at the Department of Consumer and Business Services as well. This is a ridiculous restriction of a reasonable and customary use of a credit card, and I wouldn't be the least bit surprised if it violated AT&T's agreements with them.
So that's pretty much the summary on AT&T. More on the sync and hardware issues tomorrow. So far, the iPad 3G experience continues to be a serious hassle and a major disappointment.
Thanks again, Apple and AT&T.