Unlocking iPhone SE

[Jony27]

Hi folks, bit of a dilemma here. Have an old iPhone SE that was on an O2 contract. I'm looking to give it to my brother who uses a simcard from the Philippines. I've rang O2 to get it unlocked and they said it would take 3 working days to complete.

My question is, if I put a non O2 SIM(possibly 3) in 4days time before giving it to my brother. Can he just pop out the 3 SIM and put his own SIM card in(non 3)?

I thought I read somewhere before that iPhones lock to the first SIM that is used on it. Which defeats the purpose of getting it unlocked?

 

[Jony27]

Thanks chaps. Was told it will take 3 working days but got confirmation last night. Had to get it connected to iTunes with my 3 SIM. Phone on its way to my bro now.