Do all phones out now have sim cards?

i have a t-mobile motarolla slider phone and if the below statement is true can i buy the cheapest prepaid t-mobile/at%26amp;t phone and take out the sim card and attach it to the motarolla slider that i have and pay monthly so that i no longer have to pay monthly and just buy phone cards and buy minuets as i go?





There are 2 different types of networks that are commonly used by service providers in the US. T-Mobile, Cellular One and AT%26amp;T use GSM networks while Verizon, US Cellular and Sprint use CDMA networks.





Phones for GSM networks use sim cards and phones for CDMA networks do not. So any phone from Verizon, US Cellular and Sprint will not have a sim card.

Do all phones out now have sim cards?
I agree with one of the answers below, most phones are locked to a service provider. ex. if you have t-mobile sim card- it will only work on a t-mobile phone. There are websites that you can buy an "unlock code" for about 20.00, just do a google search or use the website below. That way you can use your sim card, just keep in mind that t-mobile won't be able to troubleshoot any problems you have if its a phone that they don't sell or "support"- hope this helps!
Reply:All GSM phones have SIM cards (phones from T-mobile, AT%26amp;T, etc.). A T-Mobile prepaid (or postpaid) SIM card will work in any T-Mobile phone, however, it will not work in other GSM carriers' phones (such as AT%26amp;T) unless the phone has been unlocked. Phones are almost always locked to the carrier unless they have been unlocked to work on other GSM networks. Once unlocked, a GSM phone will work on any GSM carrier for voice, but data services may not always function property. If you contact T-Mobile customer care, they may be able to port your existing phone number onto the new prepaid card. Otherwise, you will get a new phone number when you activate the new prepaid SIM card.
Reply:No, not all cell phones have SIM cards. I have Verizon as my service provider, and they use that CDMA technology, which doesn't require one in my PDA.