Adrian Caspersz wrote:

Got an elderly friend who categorically does not wish to have a smart
meter fitted. EDF have apparently sent letters and are getting rather
stroppy.

Ask EDF if they wish to lose a customer?

Can't be enforced, can it?

No.

https://www.ofgem.gov.uk/consumers/household-gas-and-electricity-guide/understand-smart-prepayment-and-other-energy-meters/smart-meters-your-rights