[bombcar]

The only one I ever saw do a switch was Republic Wireless (very early on they were on Sprint IIRC, and then slid over to Verizon or something, I wasn't paying much attention) but that has a whole separate VOIP over phone/wireless confusion to deal with.

[toast0]

Yeah, Republic Wireless was started by Bandwidth.com, a registered CLEC and leading provider of wholesale telephone services. It's not surprising that they'd have the wherewithal to build their MVNO with switching in mind, or that they owned the voice calling portion.

Apparently it was spun off in 2016, and is now owned by Dish. And looks like they switched to ATT and carrier based calling. I'm just summarizing wikipedia though; I don't know if there were SIM replacements or if the SIMs were network independent so they "just" had to have a different network allow attachment.

[bombcar]

I used them for a bit right after they switched, and iirc it was a shitshow technically, this was BEFORE everyone had wificalling as an option, and the phones had to be relatively specific Android models, and there were some older ones you had to send back to get a new one or you had to limp along on the old network.

I didn't care because I was 99% wifi at the time anyway.