Hi yes sure you can use your sim card in iphone only if it is unlocked one .Else if the iphone is locked to some other network provider then until you unlock it you can't freely use it with your sim .You can easily unlock your iphone with the help of providers like Mobile-Unlocker.com here they are rendering remote unlocking service to unlock all model iphone from network lock .You can make use of it and unlock your iphone then freely use it with any GSM sim ...