Hi @Anonymous User
If you are referring to the generation 1 smart box with the inbuilt Freeview tuner, then all you need is a television with a HDMI port, together with a TV aerial and an internet connection of 2.5mbps or higher.
With regards to the newer nowtv 4K smart box the only compatibility issue would be with the nowtv smart remote, where the IR commands saved in the remote doesn't match the IR codes on every television manufactured.
The IR command codes only effects two buttons on the nowtv smart remote controller, which are TV on/off standby button and volume adjust button that can be used to operate the TV.
The nowtv box is based on the Roku boxes and the IR TV command codes saved on the nowtv smart remote should cover the main big TV manufacturers such has Samsung, LG, Sony Panasonic etc plus other brands sold in the USA.
However like you mentioned it can't cover every brand of Television in the world and some of the more obscure TV brands might not be covered with the two button IR codes.
What TV manufacture and model are you thinking of buying, where perhaps somebody on here is using that brand TV with the nowtv smart remote ?
I have a Panasonic TV and the nowtv smart remote works fine interacting with regards to the TV on/ off standby and TV volume sound adjustments.
