I have sprint, Can I use At&T Iphone 4S? I lost my phone and only have this one?

I want to know if Sprint will let me use a At&t Iphone 4S? I know T-mobile and other companies let you use other companies phones. Would I have to pay extra?

WILL BOOST LET ME USE A PREPAID LG SMART PHONE /

Big maybe. Sprint is like Big Red--they use CDMA signals. ATT and Tmob use GSM signals. BUT if ATT will unlock it, it's probably just a question of with a Sprint SIM activating the CDMA receiver in the handset. 4s was the first iPhone to have dual bands (it could use either) so they didn't have to have Foxconn run two assembly lines--1 for each signal.
1. ATT phone has to be unlocked--you can call them or check website on process to make that happen.
2. See if Sprint will let you hook up on that line.
3. Report your phone stolen so the serial number will be deactivated--and if you have insurance maybe make a claim.
Best luck.

It a possibilities, you can contact sprint and ATT. But some company prefer to get their own phone, I Ihave a Iphone for ATT but it was unlock and I used with Tmobile.