KEND wrote:Thinking of buying a Samsung smartphone with double sim card. Is it possible to have 2 simcards from different carriers in different countries
Yes, it's no problem at all. The technology of the mobile phone and the carriers is designed for international use and I currently do it every day here in China, as well as when I travel to other countries. The phone allows both SIM cards to be essentially simultaneously available to receive SMS texts and voice calls.
If my base country is China and I travel to the UK, I can leave my China SIM in my phone and receive voice and SMS, then install a local UK SIM to have a local number, cheaper data, cheaper outgoing calls, whatever.
On the internet data side, you manually choose which SIM card to use and you can easily switch back and forth between SIM's with around 10-30 seconds transition time.
Side note: for internet data, if you roam internationally and use a SIM card from country Y inside of country X, the carrier network inside country Y will route your internet data back to country Y.