The train service are advising passengers that some services are expected to be very busy this Saturday.
It's due to a number of events taking place across East Anglia.
Ipswich Town are taking on Peterborough United away, Norwich City are playing host to Newcastle United, Colchester United are at home to Cambridge United and the Country Fair Raceday will take place at Newmarket Racecourse.
They say there will likely be large queues and very busy trains, particularly on the Ipswich to Peterborough line.
Extra members of staff will be on hand to help due to the expected amount of passengers, and they are advising commuters to buy tickets in advance to reduce waiting times at stations.
James Steward, Great Anglia's Area Customer Service Manager, said: "Trains and stations are expected to be very busy on Saturday 17th August as people make their way to and from these popular events.
"People should buy their tickets in advance where possible and allow more time for their journeys.
"We are running longer trains where possible and practical, but passengers may wish to consider alternative arrangements."
You can check for alterations to services via the service's app, website or Twitter page.