I'm with TMobile in US and pay for a global plan where I can use the phone. As I was working abroad in France and England for 2 months, using my Iphone for managing my work here in the US, I had to make a lot of calls. I used WhatsApp, FB and FB Messenger when I had good internet connection but when I was out of good wifi range, I used Google Phone which wasn't as reliable as being on the TMobile roaming network but worked better than the internet based phones. TMobile charged me $427 for calls made in the month of Aug and threatened to cut me off if I didn't use Wifi instead of their phone. Odd that they not only charged me a hefty amount but then threatened me for buying their service and paying handsomely for it. As I didn't want to change my SIM for a local SIM, I was afraid that changing SIMs (which has happened in the past) changed my US number to the local SIM number. I didn't want some of my clients knowing that I was not in US if they called me on my US number and it didn't ring. TMobile has been wonderful for the 5 years I've had it. They charged me for using their services internationally and I've been fine with that. This time they not only charged me a lot but also threatened to discontinue my service. Sheesh...