I would like to recommend the services of Jon Aspden (Testit). After being let down by our previous electrician and after a number of absolutely ridiculous quotes (and unreceived follow-up quotes) we found Jon.
Jon arranged the upgrade to 3phase, re-wiring to my bakery with submain and as I had a new European commercial oven plus two other (European) heavy duty appliances to connect to it, he sorted out those too with 3-phase powerpoints etc.
I must say amongst a sea of disappointment, he has been a beacon of hope!!! Reasonably priced service, punctual, polite and reliable.
Thank you Jon!