Now new iPhone 5s, 6 and 6 plus are available as SIM-free in Japan. I have my T-Mobile SIM. If I buy a SIM-free iPhone in Japan, can I use it with my T-Mobile SIM? I concern if I can use wifi-calling with the T-Mobile SIM with an iPhone 5s, 6, or 6+ in Japan.
iOS 8
No. Sim free does NOT mean unlocked. No iPhones sold in Japan are unlocked. They can ONLY be used with Japanese carriers.
Not true. If you buy an unlocked ("SIM Free") phone from the Apple Online Store in Japan you can use it with any carrier in the world, at least as far as GSM is concerned. Using it with CDMA carriers is s a different matter, but that has always been the case for iPhones. There are basically two reasons you would want to buy a SIM-Free phone from Apple Japan: 1. It is accepted by any carrier in Japan (so you can sign up for service if you live there), and 2. It has broader LTE coverage than the model sold in the US. Also, note that at least docomo restricts the functionality of foreign unlocked phones if you are using a docomo SIM. You will not be able to change the APN (and thus not use personal hotspot) unless the phone was purchased from Apple Online Store in Japan.
sim-free iPhone 6 in Japan
