In a response to an Engadget inquiry on the subject, AT&T has said that it “cannot provide any details at this time” as to when, or if, U.S. iPhone users will receive the option to use the phone’s built-in tethering feature. “We know that iPhone users love their devices and mobile broadband, and that they’re likely to embrace tethering just as they have other features and apps – by using it a lot,” the company said in its response. “iPhone tethering has the potential to exponentially increase traffic, and we need to ensure that we’re able to deliver excellent performance for the feature – over and above the increases in data traffic we’re already seeing – before we will offer the feature.” AT&T Mobility CEO Ralph de la Vega said in November 2008 that tethering support would be coming “soon;” built-in support for the feature was added to the iPhone OS in June 2009, but AT&T said in October that more “fine tuning” would be required before it launched the feature.
AT&T keeps iPhone tethering on hold due to traffic concerns

Charles Starrett
Charles Starrett was a senior editor at iLounge. He's been covering the iPod, iPhone, and iPad since their inception. He has written numerous articles and reviews, and his work has been featured in multiple publications.