There are a handful of suppliers I know of who are capable of installing 3-phase meters. Mostly the former Big 6 but other smaller ones are also capable. I'm with OVO myself and have confirmation from them that they're able to do three-phase meter upgrades for about £325. It's not just businesses that have them either, some homes do now. It's more of a case that half the industry is slow to catch up and many still consider three-phase to be a business thing.
You'll need to switch supplier in order to get this work done in any realistic timeframe. I will leave it to you to decide who to go to.
Just another guy passing by... The unknown tech way...
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