Not too long ago, I wrote a blog post where I talked about AT&T’s Bandwidth Throttling policy, along with what appeared to be some sketchy accounting or buggy bandwidth utilization counters on the iPhone. In a nutshell, there’s a discrepancy where it appears that AT&T is billing me for 73% MORE bandwidth than I’m actually using.

It’s now been a week since I wrote that post, so I decided to check my utilization today. The iPhone is reporting 76.5MB of sent traffic, and 140MB of received traffic, for a total of 216.5MB. Seems about right, based on how my usage has “felt” over the last week.

Checking out AT&T’s website is something else entirely. According to their calculations, I’ve used 544.37MB. By my math, that’s 151% MORE than what the iPhone says. The pattern here is extremely alarming, and the discrepancy is well beyond what I’d consider any reasonable amount of error. My conclusion still stands: either the iPhone can’t track bandwidth usage correctly (something Apple needs to fix), or AT&T is grossly overbilling me.

I’m still going to continue to track this, but this is starting to get ridiculous. Has anyone else out there been comparing their data use? I’d like more data than just my experiences.