This is untrue. Only VZW iPhone 5 is unlocked. If you buy an AT&T phone with a contract it comes locked, as does Sprint IIRC. (T-mobile I think no longer offers contract pricing so all of their phones are unlocked.)
No need to look any further all the information is right here. We can unlock your phone if you are looking to use it internationally. You may have the account for more than 90 days and have no interuption of service. If you are going to be traveling we encourage you to reach out to our Global Support team where they can advise of the charges http://vz.to/17KseUf
Follow us on twitter @VZWSupport
Well, Verizon needs to do a better job of educating its sales and technical personnel, then. Today I talked to three different employees in two stores, plus the e-mail contact with Verizon support above in this thread, and I got conflicting answers. I was told that (1) Verizon will not unlock phones, (2) Verizon will permit a foreign SIM card only for a limited time, (3) the employee had no idea of the answer, and (4) the message from Verizon support above, which states that Verizon will unlock the phone if you are traveling internationally (which implies that the phone is not "already unlocked"). However, the Verizon Global Support FAQ page does state that at least some 4G phones are unlocked. See this excerpt from the page:
Yes, you can unlock your device to use local service. The steps required to unlock your device vary by the type of device you have:
I assume the iPhone 5s is a "4G global ready device" (it has both GSM and CDMA antennas, from what I understand), although the FAQ page does not state which devices it means.
So, how does one know what to believe, with so much conflicting information from Verizon? I will probably call the Global Support number, 800-711-8300, for an answer, because I do not want any unexpected surprises when I arrive in Spain and try to insert and use a SIM card bought from Vodaphone, Orange, Movistar, or some other Spanish provider.