Here's a how-to in putting in a SIM to a Samsung Galaxy S4 Mini...
Both the Samsung Galaxy S5 and Galaxy S3 have micro-SIM cards. So, it should work.
no
no
There is a dual SIM variant for the Galaxy S5. However, it's only available for the China market.
NO
The Samsung Galaxy S4 Mini uses a micro SIM card. When replacing or inserting a SIM card, ensure it is properly formatted to avoid compatibility issues. Always power off the device before changing the SIM to prevent potential damage.
Galaxy S 4G phone - Earbuds -Manuel - new SIM Card
You can purchase sim network pin for Samsung Galaxy S3 from any vendors online like Unlock-Zone.com
you have to put a sim card in every phone, if u e=want to save stuff
u put it uder the sim card ....
When you buy it, it doesn't come with a sim card, but there's a place to insert one on the side. :)