Verizon Wireless has surprised a lot of customers by offering the iPhone 5 unlocked out of the box. According to Engadget they have no plans to re-lock the device with any future iOS updates either! This means that customers can easily use the device internationally or even switch to an AT&T sim, however, LTE on AT&T’s network won’t work and you’ll get HSPA+ 4G speed.
In order to take advantage of LTE the international carrier must be operating on the following bands: Verizon's CDMA model A1429 supports CDMA EV-DO Rev. A and Rev. B at 800, 1900 and 2100 MHz; WCDMA/HSPA+/DC-HSDPA at 850, 900, 1900 and 2100 MHz; GSM/EDGE at 850, 900, 1800, 1900 MHz; and LTE Bands 1, 3, 5, 13 and 25.