Do different networks carry different Sim cards?

Do the phones that have SIM card holders, hold all SIM Cards? Like do different networks carry different Sim cards?, is what I'm trying to ask. Because I found a phone on Amazon, that is unlocked, and I have Tmobile. I lost my phone recently, so they're sending (if it's possible) me a new sim card, but I rather have the phone I found on Amazon.

Do different networks carry different Sim cards?
There's a SIM card standard that is used by all cellular providers. All that belongs to the cellular provider is the number (i.e. the way they bill you), but the SIM will work in all phones regardless of which provider you use (the SIM is supposed to work on all types of phones cos they don't own the phone manufacturers like Nokia, Siemens, etc).





When u get your unlocked phoned, pop your SIM in and it should work fine. Where your SIM goes into your new phone as compared to your old phone may differ, but your phone manual will have instructions on where to insert it in your new phone.





I had an extensive answer for someone else regarding SIM cards, you can check it at http://answers.yahoo.com/question/index;...
Reply:All SIM card holders inside phones are the same but to use any SIM in one phone it has to belong to that company or be unlocked. If you buy an unlocked phone then yes all you need to do is just put your SIM card in it and you're all set.