AfC Info website - Kingston and Richmond

If you hold a valid Blue Badge in the European Economic Area, you're eligible to register for a 100% discount, even if you don't own a vehicle or drive.

You can register up to two vehicles that you would normally use to travel within the Congestion Charge zone. This could be your own vehicle, or one you travel in.

See ful information on the Transport for London (TFL) website about blue badges and the congestion charge