Govia Thameslink says it has had a “positive start” to the new timetable introduced this week.
Some 200 extra trains are now running each weekday across the network compared to the period prior to the introduction of the May timetable.
The firm states that levels of punctuality and reliability are returning to levels achieved before the May timetable change.
GTR chief executive Patrick Verwer said: “My priority is to ensure passengers have the punctual service they are promised, and the new interim timetable is starting to achieve that.
“While the overall picture has improved, some infrastructure problems beyond our control have impacted services.”
Season ticket holders affected by disruption since the May timetable was introduced will be able to claim special industry compensation. This is in addition to the company’s Delay Repay compensation for delays of 15 minutes or more.
Passengers are encouraged to find out more by visiting www.thameslinkrailway.com or www.greatnorthernrail.com.