AT&T has introduced a new “Mobility Administrative Fee” to its postpaid contracts. The $0.61 monthly fee ($7.32 per year) is being categorized “below the line” alongside tax and fees as an administrative surcharge. The fee came into effect on May 1st, and applies to all consumer contracts as well as “IRU” business contracts (business accounts where the user pays the bill). It’s a small charge for the individual consumers, but given that AT&T’s postpaid subscriber base stands at over 70 million, the move will net AT&T hundreds of millions of dollars — somewhere around half a billion dollars, in fact. That’s a lot of extra revenue from one little charge. AT&T tells us that the administrative fee will “help cover certain expenses, such as interconnection and cell site rents and maintenance.” It also added that the charge is “consistent with similar fees charged by other carriers.”