We have had an experience when we have been out of country and trying to call home or 1-800 number and were not able to dial properly because we didn’t know how from where we are.... Was super frustrating, cause we were at the hotel and they couldn’t find our reservation....
For that particular purpose, I got a TextMe app for my phone. Here is how it works: the app is using wifi /internet and works as VOIP. You can call any North American number from anywhere in the world as long as you have data/ wifi/ internet connection. You dial just like you are back home. Area code plus the local number. Works like the charm!