In the latest tit-for-tat in the escalating jockeying between carriers, Verizon has modified its Edge payment and early upgrade plan. Until now, customers had to wait six months to upgrade. Now they can do it after 30 days.

Verizon Wireless

The move comes shortly after rival T-Mobile announced at the Consumer Electronics Show that it would pay customers looking to switch from AT&T Mobility, Sprint or Verizon up to $650 in early termination fees.

Verizon said that eligibility will require news customers to pass credit checks. What's more, it said that prepaid accounts are not eligible for Verizon Edge.

A spokesman for Verizon said "this is currently a promotion but we have not set an end date. It is in response to our customer's requests regarding this popular payment and upgrade plan.....While it is important to understand what our competitors are doing, Verizon makes decisions based on what's best for both our customers and business."