How do I remove all information from my SIM card?

Question

Hi. I just got a new phone (Galaxy S5), and so I tried to remove information from my old phone, the Stratosphere 2, and I almost did.

But, whenever I boot up the phone it still shows my number on the old phone and wants to activate the phone for that number. For example, when I use the web browser I was hoping it simply would not work, and instead it goes to a website with an option to activate the old phone. This sounds scary if I lose the phone as someone else can activate the phone with my number.

I noticed when I took out the SIM card, it no longer remembered my phone number.

So, before I give this phone away to anyone, how do I delete everything on the old SIM card for the old phone?

tbo27 · Accepted Answer

The Sim holds programming and plan info.  Just take it out and discard.they'll need their own Sim and factory reset phone with no sim