score:4
All charges are based on the locale of the phone number, or the home region of the SIM, not the device itself.
Your friends will be texting/calling an international number and it will be charged at whatever rate plan they have for international texts or calls.
If your friends have included international calls/texts, there would be no incremental charge.
Also be aware that this applies only to carrier SMS. WiFi/Internet messaging such as iMessage or WhatsApp use a data plan or WiFi.
Upvote:2
Yes, texting you will count as international texting (even if you stay next to a texting person!) and correspondingly charged (if there are different rates for national and international SMS what is not always the case).
It is not your location what counts but your phone number and it remains foreign.