The cost of the Young Person’s Travel Pass is to go up £10 to offset an increase in bus fare prices rises.
The scheme, introduced by Kent County Council in 2014, offers free use of bus services Monday to Friday between 6am and 7pm.
It was announced last month that children using Arriva buses would also be able to use the pass outside of these hours and at the weekends and during the holidays from May 6.
Stagecoach bus users can also make use of the extended hours.
The pass will now cost £290 and applications for its use from September open on June 4.
The pass, which helps around 25,000 children in Kent, will remain at £100 for low-income families.
KCC cabinet member for transport Mike Whiting said: “Nobody wants to see prices increase but unfortunately, as fares rise, we are in the unenviable position of having to put the cost of the pass up.
“I believe this is still the most generous scheme outside of London. KCC does not have to provide the pass but we do so because we want to promote sustainable school travel on the public bus network.
“Parents have a choice to get the pass or pay the operator the bus fare direct, which in some cases could cost up to £740.
“Our scheme, which is subsidised by the taxpayer at about £300-£330 per pass, costs around £1.50 a day. With the extended hours of use, I believe this offers extremely good value for money.”
KCC provides £8.5 million to the scheme each year and the new extended benefits have been introduced at no additional cost to the council.
The county council allows parents to halve the cost by purchasing half-yearly passes.
Kent Youth County Council Transport Committee chairs Kyle Siwek and Freddy Waters said the scheme still offered good value for money.
Mr Siwek said: “The Young Persons Travel Pass allows students to travel to school for £1.50 a day, which provides better value than buying tickets on the bus.
“We are grateful to KCC for continuing to support the pass.”
For more information visit www.kent.gov.uk/youngpersonstravelpass