Rail operator, Govia Thameslink Railway (GTR) is inviting season ticket holders in Huntingdonshire to claim additional compensation for the May timetable disruption in the latest phase of the industry scheme.
GTR has already contacted 63,000 passengers for whom it has postal and email contact information.
Now, other season ticket holders, who have not yet been contacted by GTR, can visit the website railcompensation.thameslinkrailway.com to see if they qualify and make a claim.
Qualifying passengers will need to have held a season ticket for travel from the most affected stations - including Huntingdon and St Neots - between May 20 and July 28 and will receive money back based on the equivalent cost of one to four weeks' rail travel.
As previously announced by GTR, the scheme will be opened in a later phase to regular travellers, such as part-time workers, who do not have a season ticket. Passengers who have made a minimum of three days' return travel in any week will qualify for a refund.
Passengers without season tickets have been advised to retain any tickets, receipts or other proof of travel where possible to support an application.
Reliability and frequency of services on Thameslink and Great Northern has improved since May, with over eight out of 10 trains arriving on time, and 200 additional services in operation, however delays and issues remain with the altered timetable.
GTR's chief executive officer, Patrick Verwer, said: "We are sorry for the disruption caused by the May timetable change and would urge affected season ticket holders who haven't already heard from us to claim through our compensation website.
"We have turned a corner in terms of performance and services are now more punctual."
Qualifying season ticket holders should make their claim by November 30.