Galaxy s3 sim card into Galaxy s5

[Alpha Mom]

I've purchased a new Galaxy S5 and will be using it on At&t in place of my current S3.

I would like to move the sim card to my new phone, I understand that this card will work in the S5. However I would like to know, since this card is from another phone, at what point in the startup process do I put it into the s5? Is it okay to put it in when I start up the phone the first time?

Do I have to contact At&t after I move the card?

I have contacts, pictures, etc backed up to my computer, so I think I'm good to go. Just need to know how to handle the card move.

Thanks, in advance, for your help.

J...

 

[PapaGary]

With both phones completely shut off, swap the SIM from the old phone to the new one. Then turn it on the new phone and you're good to go. AT&T won't care as long as you keep paying your bill.

(Now this assumes that both phones use the same size SIM.)