Tends we live in a row of cottages and the phase is split between us so every third house is on the same phase

Pretty sure that’s standard for the UK

It is. I remember when we had a power cut and when I went outside I could see that only a single phase had been lost - every third house had gone dark, the rest remaining lit.

I reported it and it was sorted pretty quickly.

Nearly everywhere in UK has only a single phase supply, it's how the grid in this country is designed.

Houses in the UK are connected to a single phase, but a three phase supply is available if it's needed — the cable is in the street, though digging a new trench to connect to it is often costly.

Larger users are presumably connected with three phases by default — that primary school in the middle of the housing estate, the retirement home that has several lifts, not-tiny shops, the small block of flats etc.