The rationale behind Verizon's November 15 move of raising its early termination fee (ETF) for "advanced devices" to $350 from $175 is being questioned by the consumer-friendly Federal Communications Commission (FCC).

In an open letter sent to Verizon on Friday, the FCC has sought an explanation about the twofold increase in its early termination fees for smartphone customers. The FCC has also questioned Verizon about the reason behind its decision to charge subscribers without a data plan for unintentionally accessing its mobile web service.

Some of the questions raised by the FCC in its rather strongly-worded four-page letter to Verizon read thus: "It appears that if a customer cancels a two-year contract after 23 months, the customer would still owe an ETF of $120. Is this correct? If the ETF is meant to recoup the wholesale cost of the phone over the life of the contract, why does a $120 ETF apply?"

Verizon had earlier reasoned that the ETF increased could be justified on the grounds that the company had to bear the cost of subsidizing handset prices, which increased greatly when customers depart before the expiry of their contracts.

However, with no other carrier following Verizon's ETF increase suit, the company is virtually out on its own against the regulators, who have given it time up to December 17 to explain the reasons for its hiked ETF move.