*67 does not block caller ID

Like many people you probably want your number blocked more than unblocked, so what I did was just have my number blocked permanently at AT&T. No matter who I call its blocked automatically. Then if I wish someone to see my number I enter their number in my contacts with the *82, then when I call that person it shows my number and they know its me. Just a suggestion.

I can't remember where I saw these and I have not tested them myself, my wife was the one interested in this..

The *31#<number> is to unblock a blocked number
The #31#<number> is to block an unblocked number

DRGEK,

*67, *82, and *70 are landline codes, and won't work on all GSM cell towers. There is a GSM code for blocking caller ID, or you can toggle it in the settings.

Hope this helps,

Nathan C.

Actually ATT tells me this is not true and Apple confirms ATT's allegation that it is a device issue. Please see this thread:

http://discussions.apple.com/message.jspa?messageID=6924615#6924615

ATT was quite specific that *82 is the ONLY official way to selectively block a caller ID. While the GSM code may work for whatever reason with the iPhone and possibly on international systems where *82 may not, if you want your domestic US Address Book to synchronize uniformly with *82, follow the procedures outlined in the other thread. It will certainly keep me from having to go in and manually change all the contacts with *82 to *31#

Well works for me. But so you know, using *67 has nothing to do with the phone (or any phone)...it is a code that tells the carrier not to transmit/block the information it sends down the line. So if anything, when it fails to work, it is the carriers issue, not the phone.

go to settings, then phone and flick down to 'show my caller id". you can change the setting appropriately. the downside is you wont be able to do it on the fly really, as much so as just dialing *67, but it will work in the same way.

There might be something wrong in AT&T's system. I would call them and explain the issue.

Doesn't necessarily mean that its not on their end. Next step would be to call Apple care and see if its an iPhone issue we are unaware of.

This link may be helpful for anyone who wants to use GSM features as part of international travel and provides insight to Nathan C's insight above.

http://www.arcx.com/sites/GsmFeatures.htm