Can I unlock an iPhone with any carrier?

Hey Im trying to buy an iPhone off craigslist! I want to use it on virgin mobile but some say AT&T or Verizon etc. So am I able
E to use it on virgin mobile!

Yes you can unlock it for any carrier. You will just need to take it to a place to get your SIM card shaved down a little bit

Lock and Unlock are GSM terms… (ATT and Tmobile and STraight Talk)… Any carrier that uses SIM Cards for Voice/text/data is a GSM carrier… Unlock means any SIm card on Earth can be used in the phone. Its no longer LOCKED to 1 carrier. Contracts dont bind the unlocking process…

CDMA carriers (Verizon and Sprint and altell and Virgin Mobile) have SIM cards for 1 purpose---4G LTE… LTE is GSM technology. But CDMA phones still use the CDMA radio for voice/text/2g/3g data… They just need SIM Cards for the 4G LTE… Next, they are not locked. They are Clean ESN and BAD ESN. ONly Clean ESNs can be flashed to other accounts and CDMA carriers. IF its a BAD ESN (original owner didnt meet contract obligations or pay bill down to $0 or reported it lost or stolen), then the CDMA carrier in charge will block the ESN from being used on any CDMA carrier on Earth. There is no hack for that. Getting a Bad ESN phone off Criaglist or ebay is a huge scam process…

GSM phones and carriers… CDMA phones and carrriers… DO NOT MIX!

Lastly… The biggest disappointment for you… Since CDMA phones cant be unlocked, you must have the other carrier's (Virgin Mobile in this case) permission to use it on their service… B ut here is the kicker… Its a CDMA Iphone… Virgin Mobile and Verizon and Sprint wont share their iphones to anyone… No Verizon Iphone on Sprint or Virgin. No Sprint Iphones on Virgin or Verizon and no Virgin Iphones on Verizon and Sprint… They are so Strict about it

So… You best bet is to get a ATT Iphone… Jailbreak it… Unlock it… And put it on straight talk or Tmobile prepaid