[edent]

No, they can't do that either.

From the TfL link above

"Since 13 January 2018 it has been an offence for companies, including private hire operators, to charge their customers a surcharge, or extra, because they are paying by credit or debit card."

Or see this news story.

http://www.bbc.co.uk/news/business-40648641

[charlesdm]

Seems to be quite a new rule. Last time I was in town was in December last year. Good improvement I’d say!