Cell phone compatability with foreign SIM cards

I should've said -- non-USA carriers AND non-USA SIM cards....

Hey J H -- welcome to the Swappa Forums!

That's a really great question. It can get a bit confusing trying to figure out which bands and frequencies a phone supports -- and whether a phone will be compatible with wireless networks outside the US.

You should begin your search by looking at unlocked phones. But as you already know, not every unlocked phone works on every carrier.

Fortunately, we've compiled a list of supported network bands and wireless carriers for unlocked iPhones in our Unlocked iPhone Buyer's Guide. So check the bands there and see if they match up with the carrier you're looking to use.

If you're looking at getting an Android instead, tell me the model you're interested in, and I can look into the supported bands!

Thanks! Given that what I'm looking for is not just compatability with USA carriers, but foreign carriers (to be able to use a foreign SIM card with a foreign phone number) as well... I've gathered that I have to be VERY careful to NOT get unlocked phones that were originally distributed/manufactured for specific USA carriers (Verizon/AT&T/T-mobile, etc.) Instead, I have to limit myself FIRST to FACTORY unlocked phones -- and THEN figure out which bandwidths the phone will support. My preference is an Android phone. (I've had the Samsung 7 Edge -- but again, I think not all 7 Edges are equal in that respect...) and would ideally upgrade to Samsung S20 FE 5g -- but again, don't think that just any S20 FE 5g will do the trick. It's mighty hard to parse through all this stuff. We're looking at Europe, Asia, Africa and Latin America, primarily....

AND -- thank you for your help!

How about a dual sim phone? I bought the s10 plus from a seller here and it works with my us sim & my mexican one too