UK Can you buy your own Supply meter?

[Wenthen]

I have a 3 phase client with SolarPV who needs a 3 phase smart meter installed to be able to register for Smart Export Guarantee (SEG) payments.
He tells me that 3 of the 'big 6' wont install a new meter - his existing one is not Smart.

Can he BUY & install his own Smart Meter - subject to the DNO approval, resetting the seals etc..?

 

[snowhead]

I doubt you can actually buy a Smart meter.
If you could, I'm certain the Energy suppliers won't accept it as it's not from a trusted source and could have been hacked or adjusted to give a false higher output reading.

If 3 won't that means 3 might, plus all the other suppliers.
It's not the DNO who would need to give approval, it's the energy supplier.
Have they given a reason as to why they won't supply a Smart meter?