Real tickets-full fare: locally, at the counters in the stations.

If you mean, without clearly stating, the RES on a pass; same same! But your expense will be a little less.

There is a fair chance that the daytime train will/has ceased to run now that holidays have finsihed more or less. You will also only get the last info -same-same!

Note that Bar is very much end of the line-so either comeback same way or pay for other transportations-bus to Albania or along coast, ferry over Adriatic.

Info on actual state of Serbije Voz is extremely hard to get without a direct local contact. Ah-the joys if old-time travel! Incomprehensible for todays juniors married with their fones

Thanks for the response but I am unsure what your answer means.

The train is still running so can we use our internal ticket or will we need to pay for a ticket?

The day train should indeed still be running (until 19 Sept.), and you can use it with Interrail. You'll have to enter the train manually.

The rail planner app is not a reliable source for timetables so what it says it not really relevant.

Your Interrail pass is valid on any train operated by Serbian Railways.

Reservations may be needed but these can be got from the ticket office.

If the train is not showing on the planner you simply add the train manually to your trip and then add to your pass. Include as much info as possible and ideally the station names in the local language.

Thank's for the answers, happily arrived in Beograd last night.

Entering the journey with a manually worked grand and got a reservation at the ticket office no problem.