Can you switch between SIM cards?

I have a Samsung Galaxy S9 which I believe can take either a CDMA or GSM SIM card. I currently am using a CDMA. However, I am planning a trip out west and I noticed that GSM has better coverage with Republic Wireless out there.

My question is: am I able to swap in a GSM SIM card from Republic Wireless into my phone for the duration of my trip while keeping my service going on my CDMA card for when I get back? I want to keep my current phone number tied to my CDMA card.

Hi @michaelp.drdopn and welcome to the Community!

What you propose is possible but not necessary and would result in paying for two lines of service (one on GSM, the other on CDMA). It’s quite possible for one to obtain a Republic GSM SIM choosing to move one’s number from a current CDMA SIM using the same phone.

Previously active CDMA SIMs may be reactivated, so when there is no longer a need for GSM, just reactivate the CDMA SIM moving your number back from GSM to CDMA.

For others reading, going in the opposite direction GSM to CDMA temporarily is a bit more complicated. Unlike CDMA SIMs, once activated, GSM SIMs expire 20 days after being deactivated. So, if temporarily moving one’s number from GSM to CDMA, the temporary move must be reversed within 20 days or one would need a new GSM SIM.

Republic’s guidance for activating a replacement phone (which applies equally to activating a replacement SIM in the same phone) is linked here:


Thank you so much! That is exactly what I needed to know.


This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.