A:AnswerNo it is not. If your current cell phone uses the same size sim card, just take the sim from your old phone and put it in the new one. Should work right away. If you are having a problem with text messages, call your cell phone company or go to a store and they can help you change the settings.
A:AnswerIt means you can use the phone on any cell network, AT&T, T-Mobile, Cricket and such. This is a GSM cell phone so your provider must use a sim card for it to work. If you travel overseas just buy a local sim card and it will work there and they will give you a local phone number
A:AnswerS8 and S8+ can make wifi calls. There is a pull down screen visible by swiping your finger down from the top of the display that has this setting. There are 3 possible settings, 1) Wi-Fi Preferred, 2) Cellular Network Preferred and 3) Never use cellular Network. You can select any one of these options. About Nigeria, I don't know, but I would assume there would be no problem
A:AnswerGSM is a network like AT&T and T-Mobile and their cell phones use a sim card. If your phone is unlocked and you travel then you can buy a sim card there at a local store and use your phone. CDMA is what Verizon and Sprint use, they do not need a sim card.
A:AnswerI don't recommend this method. But, if you choose to do it this way, make sure the glue doesn't get on any part of the circuit. Otherwise, there goes your sim card.
Good luck!
A:AnswerI have sprint but did not want to lease a phone. You will still pay for your plan per month but will not have to lease a phone. I had to by a 10 dollar SIM card for sprint, but it is well worth it to have a nice phone and not pay 35 dollars a month. I brought a cheap moto gen 6 but I was not pleased with the speed and returned it and paid the extra money for the S8+
