And it's not the same, so sometimes there is just "transit", although transit here should I guess be understood very loosely. I also assume they just know who paid for what.
Edit: although upon re-reading I think you probably asked something else. Sorry in that case.
Disclaimer: I'm working for an actor in the electricity market, although not on the business side so I don't know everything about it.
They do know who paid for what. And actually anyone is able to know. It's a very regulated market, and most of its data is published, although I have to admit that if you don't know how to fetch it and read it, it's a bit hard to figure out by yourself.
E.g. trading https://www.energy-charts.info/charts/energy/chart.htm?l=en&...
Physical flows https://www.energy-charts.info/charts/energy/chart.htm?l=en&...
And it's not the same, so sometimes there is just "transit", although transit here should I guess be understood very loosely. I also assume they just know who paid for what.
Edit: although upon re-reading I think you probably asked something else. Sorry in that case.