As long as one can obtain a SIM card from any cell carrier, an unlocked mobile phone can be used on any carrier. Also, if one is travelling overseas and obtain an international SIM card, calls can be made much more cheaply.
You will have to first get the phone unlocked.
You can't get a T Mobile service on a phone that's not T Mobile unless you get it unlocked. Once the phone is unlocked, you can use your T Mobile SIM card on it or any other GSM SIM cards worldwide.
Unlocked phones can be used with any carrier, so it will support T-Mobile.
Unlocked mobile phones enable you to choose which service provider you use. This Enables you to find the best deal available for phone charges, rather than being stuck with the network that has locked the phone.
Sometimes... With T-Mobile and AT&T you can used the cellphones offered by these two companies with eachothers service. For example if you buy an unlocked i-phone (which is an AT&T phone) you can use it with T-Mobile. You can do this because they both use the GSM network which requires SIM cards. However you cannot use an unlocked sprint or Verizon type phone with T-Mobile or AT&T because they do not use the GSM network.
Most cell phones are manufactured to be used on one specific cellular network. An unlocked cell phone is one which is not tied to any one cellular provider. When a phone is unlocked, it means it can be used on any network. The tricky part is that only the phones with SIM cards can be unlocked. You cannot use an unlocked phone with Verizon Wireless and other non-SIM networks. Currently, T-mobile and Cingular are the two networks in the United States that accept unlocked phones. Be sure to check your network before purchasing an unlocked phone, as they are very expensive and usually not returnable.
an unlocked phone could mean one of two things. One, the phone belongs to a GSM carrier (like T-mobile, or AT&T) but being that it is unlocked you can use it with any carrier that requires a sim card. The second can mean that it is a CDMA phone with GSM capabilities normally on a Sprint or Verizon Global phone meaning it is a CDMA phone with a sim card slot and as long as it is unlocked it can be used also with any other carrier that requires a sim card. However it has nothing to do with what is on the actual phone, so even if it says T-mobile it can still be an unlocked phone.
Because the mobile networks are different. You will have to use a local (NZ) mobile network if you want to use the phone in NZ.
If the unlocked phone is an IDEN network phone then yes. If the unlocked phone is a GSM phone, meaning it was previously locked to a GSM carrier (i.e. AT&T, T Mobile) then it would not work on Boost Mobile as this carrier uses a different technology, which is not compatible with GSM based phones.
No - the phone is the item unlocked - not the SIM card. If you were to replace the Optus SIM card with (for example) a T-mobile SIM - it would register to T-mobile. You could swap the SIM card back with the Optus card, and still use it.
I put in a tesco sim in a voda phone mobile but it has pin code on the screen, how do i unlock it?
i have at-mobile blackberry and once they unlocked the phone, i could use it in india.