Power to the home in the UK
Note that he three phase is 230V phase to neutral, 400V phase to phase. 

The lions share of UK domestic property is single phase, 230V Phase to Neutral (Usually closer to 240V in reality), and for 40A you would be needing a special purpose circuit installing, you will not (with the exception of some folks who run big machines) see a domestic outlet bigger then 13A (~3kW), but a special purpose circuit can be installed by an electrician. 

The common connectors used for such things are Blue 32A or 63A IEC 60309 connectors, in 2 pole plus earth 6H configuration, but they are not something you usually see in domestic situations (I have a 32A example installed in the shed for a welder). 

Most UK housing is has an incoming supply fused at either 60 or 100A, with three phase very much the exception rather then the rule, assume single phase is what will be available unless you are selling to light industry.