According to reports, it has been noticed that the unlocked HTC 10 actually comes with WiFi calling support. This means that you don’t necessarily need to be locked to any particular carrier if you wish to take advantage of the feature, but the only catch here is that the carrier you are connected to needs to support the feature to begin with.
So if you are hooked onto a carrier that does not support WiFi calling out of the box, then we guess you’d be out of luck if you are trying to use the feature. According to the folks at Android Central who have tested it out for themselves, they claim that they found that it works in the UK with local carrier EE, and it also works in the US on T-Mobile.
So if you are still considering whether or not you should pay full price for the unlocked model or sign with a carrier, know that the unlocked model will afford you WiFi calling features that were previously thought to be limited to carrier-only handsets.