5 of the 27 circuits we list will take a 4 year old, across 5 counties. The options are the same for 5 year olds.
This is the part that catches people out. Nearly every circuit sets a minimum height alongside the minimum age, and both have to be met. A child needs to reach the pedals with enough leg left to brake hard, and see over the wheel, and a kart has almost no adjustment.
One circuit opens up at this age that would not take a 3 year old:
Aviemore, Highland
A 550-metre outdoor circuit at Aviemore with the Cairngorms as a backdrop, and one of the more interesting layouts in Scotland — six metres wide for overtaking, sweeping bends on positive camber, undulations, and a long straight down one side.
Brentwood, Essex
Brentwood Karting runs an 825-metre floodlit outdoor circuit at Warley Gap, about fifteen minutes' walk from Brentwood station and half an hour from central London. It holds the International Rental Karting Award for Best Customer Experience.
Price not published
Purfleet, Thurrock
Lakeside Karting sits on the A1306 Arterial Road at Purfleet, about half an hour from central London and a few minutes from Lakeside Shopping Centre. It holds the International Rental Karting Award for Best Customer Experience, and is run by Lets Go Active, who also operate Brentwood Karting.
Price not published
Hoddesdon, Hertfordshire
Rye House at Hoddesdon is one of the best known circuits in British karting, and the operator leans on that history, describing it as the track where champions began their careers. It runs a main GP circuit and a separate bespoke junior circuit.
Worcester Park, Greater London
Surbiton Raceway at Worcester Park runs three separate outdoor tracks, which is more than almost anywhere else we list, and it means the age bands are properly catered for rather than fudged with restricted karts.
Price not published
Our guide to karting with children covers all of this in more detail, including what they should wear and whether it is safe.