Hi, I'm with AT&T USA and I'm traveling to France soon and would like to swap out SIM cards. I bought my previous iPhone 5 under contract from them about 1.5 years ago. Now I have an iPhone 6 that I bought out of contract for full price from Apple. My iPhone 6 is the device I'm using. Are IMEI numbers associated with a single device or are they transferred between devices upon upgrades? Like, did my iPhone 5's IMEI number transfer to my iPhone 6? What I'm asking: is my iPhone 6's IMEI number locked because I am still under contract with AT&T or was the IMEI number associated with my iPhone 5 the only thing that was locked (because that was bought under contract)? Under these circumstances, would by iPhone 6 be technically unlocked? I don't really want to get into IMEI lock-checking services, as I've read most of them are scams or unreliable at best. Thanks in advanced. EDIT: If I bought my iPhone 6 from Apple, does that mean it's already unlocked then since I didn't buy it from my carrier?