I took a faulty locked (to O2) iPhone 4 into an Apple store and they gave me a new one. Will it be unlocked (as they are from the store when you buy one) or will it be locked to O2 because my old one was?

I ask because I have sold the replacement phone but the buyer is saying it isn't accepting his sim.

Anyone know?

Direct from Apple will be unlocked.

Double check with your buyer to make sure it's not crossed wires regarding a micro SIM.

I've rang Apple and they say it is locked to O2. I specifically asked the Apple person in the store if it's locked to O2 like the fault phone I took in, and she said no, 100% unlocked for any network. Because of this, I advertised and sold it as unlocked.

Now I've had to put £15 on an O2 sim and post it to the buyer so I can unlock it. Plus I've refunded his postage fees because none of this is his fault. Stupid Apple employee has cost me £25. I just hope he accepts my apology or there'll be some bad feedback coming my way...

Warranty replacements from apple are like-for-like, as you're already aware, making my reply somewhat redundant.

Hope the buyer accepts the £15. I know I would.