I am getting an estimate from Uber X for 37 pounds from LHR to my hotel in Marylebone, which is just inside the congestion charging zone. Since Uber X cars are not taxis or (usually) licensed limos, they must be subject to the congestion charge.

It's not mentioned in the estimate, does that mean the driver has to eat the charge if their car is not a domiciled inside the zone? Or do they add it to my bill?