From Fairphone's US order page

> Critical Notice: The device does not support LTE Band 13 (Verizon's primary coverage frequency).

Presumably that frequency isn't used in Europe? It also says that it's "not certified for use on the Verizon Wireless network." I don't know if that means Verizon might block it (which sounds like a very US thing) or it's related to not supporting the frequency that Verizon uses for LTE.