iPad SIM is Invalid. Please try a different SIM (E000001) error.

I actually have the same error and a very similar story! I've been goolging ways to correct this, but I haven't found anything that seems to be a legit fix. Hopefully, someone will assist us sometime soon!

Ok, first of all, I am sure you used an AT&T sim, correct?? If so, then the other problem is that you have to start it wtih your wife's sim first then switch to yours. Or if you tried to use your sim but sync with your wife's iTunes, that wouldn't work cuz it's 2 separate identities. Apple is too stupid to recognize it.

Hmmm, I'm not sure I understand.

My iPad had AT&T 3G and, for Christmas, I got an iPad 2. Rather than keeping my 3G account with the old iPad, I decided to transfer the AT&T plan to my new system. After I made the transfer and got it to work, I found out that the person I was giving the iPad 1 to wanted to have AT&T 3G. I decided I would go ahead and set the iPad 1 up with 3G before I gave it away as I didn't want to burden them with setting it up.

Long story short, the iPad 2 works while the iPad 1 doesn't.

Now, like you said, both came with an AT&T SIMs card. But what I don't get is your comment about "start with the iPad 1 and then flip to the iPad 2." What are we flipping? Am I taking the SIM card from the iPad 1 and putting into the iPad 2? Or are we talking about something else? And, if I were to transfer the SIMs cards, wouldn't that mess up my 3G? I thought the 3G was synced with the SIM card....

Sorry if this response sounds idiotic, but not everyone is blessed with tech-savviness like some of our Mac experts out there.

So, after spending an hour on the phone with AT&T, I've discovered that this is an AT&T error and not an iPad one. I'll share what I found out...

After telling the representative our little story, AT&T came back saying that the error is actually an AT&T error. According to the rep, you'll need to purchase a new SIM card. AT&T voided your old SIM card, which is why it's not working. They can't reactivate it so it's pretty much "junk." You'll have to visit your AT&T store or call an AT&T rep. Once you purchase a new SIM card, you might have to call AT&T to have them activate your card.

Needless to say, your SIM card needs replacing. Oh, and if you're going to call them, you'll need your Cellular Data Number (found in settings > general), name, and e-mail handy.

Hope this helps!

Thank you! I have several business iPads and run into this when I open more than one wireless account. Of course, I have to have several, so I think the answer is to speak with AT&T FIRST, and combine them if possible. That way, the new accounts may not shut down those that were opened before it. I'll let you know when I talk to them. Thank you for the heads up.

For what it's worth, this is what I found out. I have 4 ipads I use for business. If you set up wi-fy accounts on each ipad using the same account number, it transfers the "usage" from one to the next. Naturally, I'm thinking that using my business ATT account is the way to go, but it's not if you are using the ipad to set up the account. MAKE SURE YOU CLICK THE BUTTON THAT SAYS YOU ARE NOT AN EXISTING CUSTOMER!!!! Otherwise, you will have this problem over and over.

It was set up this way because they originally thought it would benefit those who were updating from ipad 1 to ipad 2. Once it "transfers," and the 30 days expire on the first ipad (for me), the sim card on that ipad is invalidated. They will give you a new sim card, but there is the hassle. If you plan to use more than one, on the same account, before you set up service, go to ATT and consolidate the accounts from the beginning. The same terms apply - meaning no contract and month to month - but for business, if you run over, service won't stop. It will add overage, but you get the benefit of quitting when you want, so there is the plus.

Bottom line: it works like any phone with a sim card. Once you add a new one to an existing account without adding a new line - your old sim card is dead. I hope this helps. Pamela at ATT was very nice and helpful to me, and I have no complaints. This is not a perfect world, and we are spoiled when things don't perform perfectly. Treating people with respect will get you what you want. Good luck!