An iPhone data plan is required when you buy iPhone with
AT&T
as your iPhone carrier in the US. You usually get the data plan when you sign your contact with the carrier.
When you sign a contract with AT&T in the US, you automatically buy an iPhone data plan which allows you to browse the Internet and go on line.
You must have a data plan with any iPhone you buy in the US with AT&T or Verizon. If you try to connect to AT&T network with an
iPhone
that doesn't have a data plan, that iPhone will automatically send a signal to AT&T wireless service and inform them that an iPhone without data plan is being used by an error.
AT&T will then automatically add a data plan to that
iPhone
to fix the problem. Of course you can at any time cancel that iPhone data plan and claim that you don't have an
iPhone
anymore, but AT&T will know you have an iPhone the minute you turn it on.
When the iPhone contacts the AT&T server, it will identify the type of phone you have as an
iPhone. You will then receive an SMS text message telling you that the wrong iPhone plan was selected for your
iPhone, and now it was corrected by adding a data plan to it. This will happen automatically by their system. You will see your bill with data plan charges added next time.
Those situations can happen if for example you buy an iPhone used or new from different stores or from a friend. The solution is to use an iPhone Data Blocker hack.
iPhone Data Blocker:
Data blocker is an iPhone hack that allows you to block EDGE or 3G data transmission to and from the
iPhone.
This means that you can have an
iPhone
with AT&T or other carriers without having to have a data plan.
The hack blocks internet access over the carrier network by providing the iPhone a fake IP address of the form 127.0.0.1 which tricks the
iPhone
that a valid IP address is assigned.
But since there is no internet through that IP, your data will be blocked. Then it is possible to add an
iPhone
to your existing plan with At&T and have no data plan with it. AT&T will not know you have an iPhone.
It is questionable why you would want to have an
iPhone
without a data plan, but if all what you want is just a phone with the ability to browse the internet with an iPhone browser over any wifi only, then this is a perfect iPhone hack for you. However, it requires an iPhone Jailbreak which is very simple any ways.
How to block data from an iPhone plan:
This iPhone hack is free and available in Cydia but you need to be careful with it and use it at your own risk. As long as the hack is active, no data transmission from or to the
iPhone
is possible.
There are two ways of installing this hack. You can install it in a way where you can turn it on or off, which is a little risky and requires you to install two iPhone hacks from Cydia, one is called Data Blocker and the other one is called Data Toggle for SBSetting.
After installing those two hacks, the data blocker is deactivated after every iPhone reboot or restart. Therefore, you must activate the hack again from SBSettings if you restart your
iPhone. If you don't activate the hack, then transmission to the internet will be open and there is a chance that during this time AT&T can pick up the identity of your iPhone and then charge you for an iPhone data plan.
Therefore, you have to quickly activate the hack by opening the SBSetting menu and tapping the data icon to turn it green which activates Data Blocker.
The other way is to install data blocker only without the SBSetting toggle. This assures you that the data is always blocked even after a reboot. But to make sure your data is blocked, simply open SBSetting menu and watch the data IP address displayed. If it is 127.0.0.1, then you are ok, and the data is blocked. If it is something else, then the hack is not working.
AT&T iPhone Plans:
Recently, AT&T found that the majority of its customers don't need an unlimited iPhone data plan. Therefore, they removed their unlimited data plan option and reduced it to 200MB, or 2GB for $15 or $25 per month instead of $30 per month for unlimited.
Go to settings and General, then Usage to see how much data you have been using.
Also, they added tethering to the iPhone data plan, so you can add Tethering with iPhone 4 or iOS 4 for $25 which will allow you to use your
iPhone
as a modem.
The good news is that current customers who already have an unlimited iPhone data plan don't have to change it. As long as they are happy with it and want to keep, it will stay.