And say if you buy a SIM in America with $10 on it, how do you know it's getting low on funds? And what about topping up - can you go into a shop and buy more time over the counter or do you need to buy it online?

Do the telecommunications companies worldwide make it complicated just to make money or is that a silly question

Kay

There "may" be a message that you are running low.

For Verizon - You can buy more minutes at many retailers, big chain stores and even gas stations. You can also make a call [even if there are no funds available] USING the phone to the service provider to buy more minutes. If you buy at store - you are given a code to use; you call provider and enter that #.

It may be same for other service providers.

I bought a plan that gave me plenty of data. I knew I wouldn't be needing much in the way of phone calls and sms. Just needed the phone to confirm bookings, that type of stuff. It was the data I wanted. My children were following us on facebook so I wanted to upload photos for them as it was their way of knowing all was going well. I used google for timetables maps opening times etc.

There was a variety of plans depending on how long and what we needed.

I didn't want the hassle of topping up so I think I bought a plan for more than I would have ended up using. Worth it for me though.