Trains in and out of Nescot's nearest station, Ewell East, will be affected by a wholesale change in timetable from May 2018.
RailPlan20/20 is an initiative aimed at improving metro and mainline services, with money invested into new trains, station and platform improvement, and infrastructure.
Trains at stations frequently used by Nescot students, including Ewell East, Sutton, Leatherhead, Dorking, Carshalton, Mitcham Junction, West Croydon and East Croydon, will be affected.
The changes come into affect around the same time as GCSE exams. This year, GCSE English exams will take place on June 5 and 8, and Maths exams will take place on May 24, June 7 and June 12.