Will an iPhone 4S Sim fit into an HTC 8X?

I'm on a 24 month phone contract with O2. With this contract I have an iPhone 4S, but I'm not even half way through my contract and fancy buying the new HTC 8X instead. This is because after years of using iPhones (previous generations), I would prefer to try out the Windows 8 software as it looks sharp, personal and unique. Despite this, I'm slightly concerned as to whether the O2 Sim-card from my iPhone will fit in an HTC 8X so that I can use that instead. Please will you be able to tell me whether it will fit?

I appreciate your support. Please don't judge my thoughts on buying Windows OS over Apple, I don't care - I personally find that Apple are now starting to fall behind on on their iOS, although their hardware is still ground-breaking! P. S the Microsoft Windows re-brand is fantastic.

It should do. Both devices use micro sims. Make sure the HTC you buy is either on O2 or unlocked so the sim is compatible as well as physically fitting.