Reservations from Karlstad to Oslo can by bought via SJ. You need a pass cover number, which @Nanja can provide you tomorrow.

Reservations within Norway are best done by phone via Entur. See this page (scroll down to Norway); they will be sent via email (Interrail will send them via the post, with extra costs).

This is very helpful! But what is this pass cover number, I never heard of thar before?

The number on the classic paper Interrail cover.

Ah okay, and I also need this number for my mobile pass for booking those seat reservations?

Some websites still want it, such as the SJ website, which is why you can still request a pass cover number from Interrail, to be able to use these websites.

Okay makes sense! Thank you so much!

This nr consists of I (capirtal Ii+ 7 digits. Not all who want it online actually do check it, there have been some reports about this, but I really dk of Sj is among them

Anyway-it has been mentioned here more as a few times that this nr should also be gven together with online pass-info

@mcadv I've written to you before that it's a capital i + 8 digits.

I checked my email that provides all my pass information. Do you mean the number (in German it's called "Bestellnummer" wich translates to "number of order") that starts with IN and 8 numbers?

No, that is something else.

If you have a paper pass, then the pass cover number is printed on the paper pass cover, above the barcode.

If you have a mobile pass, then you don't have a pass cover number but you can request one via customer service. But since they are currently very busy and take weeks for non-urgent requests, Eurail staff, usually Nanja, can also provide one.

Okay, then I am going to contact Nanja! Thank you!

As far as I can see when I checked the at SJ.se (the Swedish Railway) there is no mandatory reservation on the train from Karlstad to Oslo. Due to construction work in Norway there are no direct trains from Sweden to Oslo right now so you will have to switch trains.  Unless you will travel on a busy day you might as well save the money for the reservation for something more fun.

The Interrail/Eurail planner says that many trains in Sweden have mandatory reservation when they don't. The only Swedish trains with mandatory reservation are SJ snabbtåg (high speed trains) and the night trains.

I see the same in the Deutsche Bahn planner: many trains in Sweden (including regional trains) with mandatory reservations. That implies that the incorrect information about mandatory reservations comes from the Swedish operators themselves.

I suppose the high speed trains are only the ones indicated by "HST” in the rail planner app or "X2” on the DB website.

The page about Sweden agrees with you: only high-speed trains and night trains require a reservation.

@Nanja, @Leo, could you ask SJ to send correct train attributes to MERITS? If reservation is possible or recommended, they should not make it mandatory in their timetable data.

 I have now checked the rail planner app, the DB website and SJ.se. HST equals X2 which is the SJ snabbtåg (high speed train). As far as I can see the rail planner app says that reservations are mandatory even for trains which according to the SJ website there is no possibility to make reservations on.

There is a list at SJ.se with routes where you can't make reservations e.g Västerås - Stockholm but the rail planner app says that a reservation for 5 EUR is required. @Nanja This should be looked into. Requiring reservations on trains where reservations not are possible to make seems very strange.

Do you have a link to that list in sj.se? (I don't mind if it's in Swedish only.)

DB also says Västerås - Stockholm has mandatory reservations, which again points to SJ having supplied incorrect data. This should indeed be looked into, since it will only confuse and deter pass holders.

Here's the link:

https://www.sj.se/sv/kundservice/fragor-och-svar.html/7829-vilka-straeckor-har-inte-platsreservation

Hi rvdborgt, Good catch, I have informed my colleague in charge of the timetable. Cheers,

Addition: it has been checked:
SJ trains to/from Copenhagen and Oslo: reservation is mandatory
Snälltåget trains, both domestic and on the Berlin route: reservation is mandatory

@Nanja @Claudi. 

SJ are still sending incorrect attributes to MERITS and as a result, the rail planner app contains incorrect information. For many regional trains, they are sending the "compulsory reservation” attribute, whereas reservation is only optional. E.g. for the direct regional Karlstad - Göteborg trains (check on e.g. 5 September, when there are no replacement buses). I'm sure @AnnaB can give more examples.

@rvdborgt @Claudi. @Nanja 

I made some checks and the regional trains between Stockholm and Örebro, via Västerås, also state mandatory reservation.

SJs website states that reservations are impossible in 2nd class on this route so it is very interesting that Interrail sells reservations to trains where reservations only can be made in 1st class. 

I also saw that the trains from Tågab are missing in the Railplanner. At least on the 5/9.

Here is info from SJ about SJ trains where you can't make reservations. 

Here again, the problem seems to be that SJ themselves are sending incorrect information to MERITS (the European Timetable Centre). Also in the DB and ÖBB planners, these trains have the "compulsory reservation” attribute:

If both DB and ÖBB are showing this incorrect information, that indicates to me that the source itself (SJ) is sending incorrect information and Interrail travellers suffer from it.

I'll see if my friend who works at SJ knows anything about this. @rvdborgt 

Thanks for letting me know, I've reported it to the relevant team. I will let you know once I know more.