My girlfriend is going to travel to Britain, France, Switzerland and Spain in Europe. How to communicate with her in China and Europe? The price is cheaper.

Every operator has an international roaming package. I wonder what carrier your girlfriend uses?

At present, China Mobile has signed the most international roaming agreements with operators in other countries, so it has the greatest possible preferential treatment.

I suggest you ask the customer service, what are the preferential ways in these countries, and they will definitely recommend you the cheapest one.