It’s unclear about Sprint iPhone 4S models purchased before
November 11. They may remain SIM-unlocked forever, though it’s
possible Sprint will be able to issue some sort of update that
So, if you’re a savvy international traveler who wants the
option of using a foreign micro-SIM in your Sprint or Verizon
iPhone 4S, now you know the deal: Keep paying your bills, and
after 60 days (for Verizon) or 90 days (for Sprint), you can call
and request that the carrier unlock your micro-SIM slot. Then you
can buy pre-paid cards to your heart’s content.
Why make you wait for this at all? This is a huge advantage both carriers have over AT&T (which won’t unlock your GSM SIM, period, no matter what).