When first introduced in 2003, the London Congestion Charge was only £5 per day. In 2005 the charge increased to £8 and £10 in 2011. Now the charge has reached £15 for any driver travelling through London during 7am-10pm every day. Those who live in London or travel through on a regular basis, can get a discounted pass, but by simply owning certain types of vehicles, you can be exempt all together.
Any vehicle model that meets both Euro 6 emission standards, have an official CO2 g/km less than or equal to 75 and also have at least 20 miles of electric range qualify for the 100% Ultra Low Emission discount. This scheme enables most plug-in hybrids and electric vehicles to be exempt from the Congestion Charge.
So, if you are looking to avoid London Congestion Charges, you would want to ensure you are driving a vehicle that qualifies as exempt from the charges or at least get a discounted pass for regular London visits.