Having just come back from Vietnam after working there for 4 months and having used a *buy at the airport* sim for my phone (which was ultr simple to install and top up thereafter), I'm now wondering how to approach things regards a trip that my wife is taking to the US.
Being FAR more cagey (and wise) than me, she would like to buy her sim card in advance and register everything BEFORE embarking on her trip. I've looked on Amazon and have found quite a few, for example, this one looks pretty good:
https://www.amazon.co.uk/MOST-SIM-T-Mob ... 06535&th=1
She's going to be travelling between Dallas (no relation mr D

Also, my wife's contract is tied to 3 (THREE), so potentially her phone is locked to the 3 network. Is this likely to cause complications on swapping out the sim for use abroad??. In my case, I have a dual sim phone that is not locked, so my Vietnam experience was pretty painless. Just hoping this US one won't be fraught with supplier hoops requiring to be jumped thro.
I'm plannning to buy imminently as she travels on the 7th, so hoping someone out there has gone thro this recently.
Just wish she loved Andoid as much as i do -life would be a tad simpler maybe

cheers
jim