It's just 61 cents. That's not a lot, in the grand scheme of things. In fact, if the news wasn't picked up and reported, chances are, you'd never even notice the extra charge on your AT&T bill. But that new mobility "Administrative Fee" is indeed there, as of May 1. It's hiding out in that litany of cell phone charges, along with all the taxes and other fees. And when all is said is done, that meager charge could wind up being a windfall of cash for the company.

AT&T has more than 70 million subscribers. Multiply the fee by the number of customers, and suddenly that little charge doesn't look so modest anymore. Over the course of a year, that adds up to something like a half billion dollars.

On AT&T's forums, one user found and posted this notice:

"ADMINISTRATIVE FEE Effective May 1, 2013, the Administrative Fee will be $0.61 per line per month for Consumer and Individual Responsibility User (IRU) lines. For more information about the Administrative Fee, please visit"

But AT&T says that it's not just pocketing the extra money. Here's the description of the charge on the company's "Additional Charges" page:

"Administrative Fee (Consumer and Individual Responsibility User (IRU) lines only)

The Administrative Fee helps defray certain expenses AT&T incurs, including but not limited to: (a) charges AT&T or its agents pay to interconnect with other carriers to deliver calls from AT&T customers to their customers; and (b) charges associated with cell site rents and maintenance."

AT&T is quick to point out that other carriers also charge administrative fees, and this amount is consistent with industry norms.

Well, that may be true, but it's still likely to rankle customers. At least those that know about it. If you have a contract with AT&T, whether individual or an "IRU" business contract (where the employee pays the bill), then you may want to check your next statement.