Phone usage and Data usage overseas:
Since early 2000's We have had a
single phone number in the USA which we can use everywhere in the world. It is a Skype number, which appears as a local number with a
Seattle area code. We pay $6.99 a month for this number. It's meant to be used on a computer but we use it on our cell phones everywhere. Here's how:
We buy a local sim card, say in
Thailand (or Mexico or...), get a new number, put it in the phone, then on the computer we log into our Skype account and change the incoming calls to be "forwarded to" to that new number.
All incoming calls to our Skype number are then forwarded to whatever cell number we happen to have in any foreign land we might be in. People calling us don't even know where we are, they call our
Seattle number and our phone rings, anywhere. If we happen to be on the computer it comes in as a free Skype call.
Anytime we call out (from the computer) the caller ID given is the Seattle number. However, if we make any calls (incoming or outgoing) from the local sim card it has nothing to do with our Skype number and they are really
cheap too.
There are other providers besides Skype which can give the same service.
Now, DATA. Always, always, the local sim cards we buy for our phone can be used for data cheaper than Google Fi, or any other major US system pitched for travelers. You just need to find out how to buy a data package for the sim card you have. For example, in Mexico we have a local sim card and we spend about $5.00 US per month for phone service. But if we want data, we add more
money to the phone and then spend some of it
buying a data package. For about $30 I can get 8GB of data (just don't start using data on your phone without the data package, that's a really quick way to use up all your time).
There are other things we do to make data and phone calls seamless and cheap. You will have fun figuring them out too.