I recived my PinePhone on Wedesday. I have been using a phone with a nano SIM card from AT&T that I have been already using. So I got a SIM adapter and it fits right into my PinePhone. I am able to make and recieve calls, and use moble data with the BT/WIFI switch turned off. Still need to get a microsd card (i know), but with the most recent UBports update w/o sd card it is working. I did need to restart the phone a couple times after putting the SIM in for it to work. Still waiting to see about texts. Just though I would share what I have experienced as of now.
Edit: I had tried to use the little adapter that came in the PinePhone box but my nano SIM did not fit (plastic was too big). I tried to use a dremel to make it larger for my nano SIM to fit, but I cut too much away so the plastic adapter that came in box did not work for me, thus I had to buy a 5 dollar adapter kit that came with a file etc, and it works. Still buggy...but again i'm not using a SD card yet.
Edit: I had tried to use the little adapter that came in the PinePhone box but my nano SIM did not fit (plastic was too big). I tried to use a dremel to make it larger for my nano SIM to fit, but I cut too much away so the plastic adapter that came in box did not work for me, thus I had to buy a 5 dollar adapter kit that came with a file etc, and it works. Still buggy...but again i'm not using a SD card yet.