I have asked this question to email support and to phone support but keep getting different answer. I would like to use my phone while in the UK for a few days for work, only for a few calls so unlocking the phone and getting a UK sim card does not seem practical to me. I know that I am suppose to go in and add International Voice Roaming but I do not have this option. Email support told me it is because I am on the $200 spending limit which makes no sense, phone support told me that doesnt matter but he could not add this either, but it "should" work without it. Please help I would like to know for sure before I leave!