Q: i have an iphone 4 which i am using in India, can the same instrument be used in USA or i need to unlock it

If the iPhone is currently locked to a wireless provider, it must

be unlocked from that wireless provider before it can be used

with another.

Be advised not all wireless providers in the US allow you to bring

an iPhone (especially an older model like the iPhone 4) onto their

network if the iPhone was purchased elsewhere.

If your iphone unlocked you can use in all networks in the world