Can I switch the SIM card between the S6 and Gear S?

[AC Question]

I purchases the Samsung Gear S smart watch because I anticipate getting the Samsung S6 soon. My plan was to be able to pop the Nano SIM card out of the S6 and into the Gear S whenever I felt like having the phone on my wrist and not in my pocket. Is this possible? I just want to be sure because my return window is closing soon and I don't want to get stuck with an item I'm not going to use.

Thanks!