Can you use a prepaid card on an unlocked GSM iPhone?

Can you use a prepaid card on an unlocked GSM iPhone?

You will need to get the correct SIM for the prepaid carrier you want to use. Often, there's a small charge.

Before you buy any random prepaid card, you must first have your phone activated on a carrier. Then, once it is activated, you can add a payment method or refill your account balance with a prepaid card. You must buy the prepaid card for your specific carrier and plan cost. In other words, if you have AT&T Prepaid on the $40 plan, but buy a $20 prepaid card, it won't work. You will need to pay the difference to get your account working.