Question about SIM cards
I currently have the Galaxy S2 and it uses a "normal/big" SIM card.
I am considering upgrarding soon to the Galaxy S4 that uses the "micro SIM" card.
I travel a lot and I dont risk traveling without a "back up phone", so in case something happens or I run out of battery, I switch SIM cards and I am back online.
So my question is.
Can I keep my old (S2) SIM card and have a new micro SIM card in the S4?
I understand that if the answer is yes I wont be using both at the same time.
Is there an expiration date on SIM cards? I read somewhere that if a SIM card is not used for a certain amount of time, it expires.
If the answer is "No", is there a work around to be able to put a micro SIM card to an old phone?
Thank you all in advance