I have an iPhone 4 that is being unlocked but I don't have data plan on tmobile. Can I still use it?
Can I still use an unlocked iPhone 4 on tmobile without having data plan?
I don't know what T-Mobile's policy is regarding this, because the only current GSM iPhone is from AT&T, and you can't use T-Mobile's 3G/4G data network with the AT&T iPhone because the frequencies don't match up. You can get 2G data, but you'd be able to do that with any data-capable phone.
Otherwise, you can use it for calls, texts and 2G.
In the current smartphone market, service providers are practically milking people off their dough in the name of data plans. Once you get a smartphone you will undoubtedly be spending around $100 to $130 on a data plan that you will probably not be using anyway.
More you got here: http://mobilerookie.com/using-iphone-without-data-plans/