How can I move my sim card from one phone to another?

[WPCentral Question]

moving sim card

moved an active sim card from a nokia 520 to a nokia 635 but the new phone give an error message of no sim card found. i have an active AT&T account. How do i get the 635 to detect the sim card

 

[HoosierDaddy]

Re: moving sim card

Sounds like the 635 may be defective or the SIM was put in wrong.