Drivers are being urged to be wary of thieves targeting people at Pay and Display machines.
Criminals pretend there is a problem with the parking machine in question.
They tell their victim that the machine has swallowed their bank card, and once the driver leaves the area, they take it and access the cash.
The council says there has been a surge in incidents like this in areas including Kew and Twickenham.
The authority is reminding people that parking machines do not swallow cards.