Motorists using the Dartford Crossing face a 20 per cent cost increase when using a pre-paid account.
Users of the Dart Charge account system will pay £2 per use of the tunnel or bridge when the new rate kicks in from October 1. This is compared to the £1.67 currently paid.
It is also possible to pay £2.50 online on a trip-by-trip basis. This cost will remain the same.
Drivers who fail to pay the charge by midnight the day after the trip are liable to a penalty fare.
Highways England announced the change last Monday [August 13].
Valerie Amar-Matthews, of Highways England, said: “More than a million people are eligible to save money on every crossing at Dartford after having signed up to the Dart Charge pre-pay account.
“After nine years of operating a 33 per cent discount for cars, the Department for Transport has reviewed how fairly the benefits to account holders are spread across different vehicle types and have aligned the Class B rate more closely to Classes C and D.”