I have an old iPhone 4s that I am no longer using. I upgraded to a iPhone 5 and transferred my number over and shut down the iPhone 4s. I will be traveling to Germany and would like to find out if I can use my old iPhone 4s by purchasing a SIM card for Germany and placing in the phone. Do I need to simply charge up my old phone and put the SIM card in for everything to work smoothly?
Definitely you will need to charge up the 4s.
In addition call the company who gave you cell phone service for the 4s and ask how to "unlock" your telephone. That enables you to use the SIM card in Germany.
I plan to do the same this Spring; AT&T said this is what I needed to do.
Edit 10/16/14: I have an IPhone 4 and have been told it will work with a European SIM card. I am using EuroBuzz. Their card is only $9. The charges are postpaid to your credit card (as opposed to European cards being prepaid). 79 cents per min on calls; 79 cents per outgoing texts (incoming free); 79 cents per MG for data. You will be given a US phone number for people at home to call and a European number for people in Europe to call you -- both on one SIM. www.EuroBuzz.com
verify you have a Quadband phone first. You will need it to work overthere.
Definately get your unlock code.
everything else should be easy.