According to Verizon, they do not lock most of their phones. To quote them directly: "We do not lock our 4G LTE devices and no code is needed to program them for use with another carrier." That means that any iPhone 5 or higher that was bought with Verizon should already be unlocked.
Using this service you can unlock Verizon iPhone X, 8, 8 Plus, 7, 7 Plus, 6S, 6S plus, 6, 6 Plus, 5s, 5c, 5 and iPhone 4S by IMEI Code. If you bought an iPhone that is currently locked to Verizon, this is the best service you are looking for.
Verizon has confirmed (here, here and here) they will unlock the SIM on the iPhone 4S, allowing for use of foreign SIM cards while traveling abroad, or for use of foreign SIM cards roaming on GSM networks in the United States (this will not allow for AT&T or T-Mobile SIM card use.)This is different than the jailbreak unlocking method; SIM unlocking through Verizon is permanent, free, and will
If you are using iOS 7 or higher, just simply connect your iPhone to a Wifi network, it will then be unlocked automatically If you have no data connection, simply load iTunes on your PC or Mac to complete the unlock (Watch the video below)