Southern and Southeastern are seperate franchises, though owned by the same company. That company is Govia, which is 65% Go-Ahead, and 35% Keolis. Keolis is majority owned by the French nationalised railway company SNCF.
For passengers though, there’s a few more perks for Southern users than Southeastern. Southern users get £2.50 quidco cashback here when booking. Southeastern offers nothing. Southern offer lots of very cheap tickets to the south coast. Southeasterns tickets to the Kent coast are much more expensive. That does not help attract daytrippers to struggling Kent coastal resorts when Brighton is 1/3 of the price.
Another thing I’ve noticed is that Southern have a nice little perk on at the moment. If you buy a season ticket you get an itunes voucher, ranging from £10 – £25. A zone 2 season ticket from Brockley to London Terminals costing £59.60 would get a £10 itunes voucher. Not bad at all. Southeastern users get no such offers, and never have in all the time I’ve used them. Oh, and an equivalent zone 2 season ticket for southeastern costs more at £62.60. That’s to pay for those high speed trains apparently. An annual is £652 a year verses £620 on Southern.
I don’t use Southern that much, but I can’t believe they are more of a shambles than Southeastern have been since Spring in terms of service and train lengths either.
The sooner MPs put enough pressure on Southeastern to rapidly improve, or strip them of the franchise, the better. Hopefully in a couple of years it will become TfL controlled, at least on Greater London routes to Dartford. London reconnections have a post about the long term hopes for london train routes to come under the TfL banner here