Why doesn't my iPhone recognize SIM Card?

I bought an iPhone 6 when I was in US. It worked perfectly there and when I came back at my hometown it says no SIM card inserted even though I have a SIM there. What is the problem?

There are some preferred network modes I.e. WCDMA and GSM check in settings and select both

If it wasn't unlocked then it wouldn't work with carriers in your country, only 1 in the US.
Also could be the frequencies used there vs your country.

Its not just a matter of buying the phone & inserting a SIM to make it work worldwide.

  • Why won't bootneuter recognize my SIM card? I just jailbroke and unlocked my iphone 2g so I could put my Verizon SIM card into it and make it work. But when I put the SIM card in it doesn't recognize it at all. It just tells me that I have no service. Did I do something wrong?
  • Why my computer doesn't recognize my iPhone anymore? When i plug my phone into the computer, it charges but it doesn't show up on my computer or itunes. I TRIED things like youtube videos and more but it still doesn't work.It worked before but not anymore.
  • My factory unlocked iphone 4s doesn't recognize my sim card? I purchased a used 32GB factory unlocked iPhone 4S on ebay and it will not activate with my t-mobile sim card no matter what I try either on the phone or in itunes. I'm pretty sure the phone is unlocked because I looked up the IMEI number online and it said the phone was unlocked. I did trim the sim card myself so it could fit in the iphone but it still works in my old phone still so I know i didn't damage the sim card. Any help on how to resolve this would be appreciated!
  • Changing from normal sim card to iPhone 4 sim card? I'm an AT&T customer with a smart phone. I'm wanting to buy an iPhone 4 but I know they take smaller sim cards than normal phones. If I buy an iPhone from an individual, can I take it to AT&T and have them give me a smaller sim card & transfer my information? Would I have to pay extra for it? Is it even possible?