Can I switch SIM card between android and iPhone on AT&T?

Ok so I have an AT&T HTC one x. I really like the phone but some days I feel like using an iPhone. If I bought the new iPhone 5c off contract, would I be able to freely switch the SIM card between phones? Any help would be greatly appreciated.

Even if it would work, it would be a bad idea.

SIM cards aren't designed to take abuse;
they are intended to be left in one device essentially permanently.

Removing and inserting the card according to your daily whims
would probably quickly result in it becoming nonfunctional,
in which case you wouldn't be able to use either phone.

If you like using two different phones,
set them both up properly so that you can just
grab the one you prefer at the moment and go.

Would the same apply for going form the htc one x to an iPhone 4? I don't plan on going back and forth but I want to switch permanently.