score:2
The Interrail rules state :
3.2 Travel in Country of Residence with an Interrail Global Pass
An Interrail Global Pass may only be used for two specific trips in the country of residence of the traveller (provided this country is an Interrail participating country). These two trips are referred to as the outbound and inbound journey.
- The outbound journey can be used to travel from any location in the country of residence to the border or an airport or port.
- The inbound journey can be used to travel from the border or an airport or port back to their (final) destination in the country of residence.
During these trips, the traveller may travel with more than one train, provided the trips are within the same day. Please note that the special rule for travel with an overnight train also applies. In order to make use of these trips, the traveller must indicate the relevant date and journey on the Interrail Pass Cover and on the Travel Calendar, in case of a Flexi Pass.
Is this allowed under Interrail rules?
I don't know how this wouldn't be, but that ZΓΌrich-Dunkirk would very much be allowed under the Interrail rules (for way cheaper too, a ticket for tomorrow from ZΓΌrich to Mulhouse can be found for β¬50)
Do I need to purchase two separate seat reservations (Zurich-Mulhouse, Mulhouse-Dunkirk) or would just one work as well? (Zurich-Dunkirk)
If you buy a separate ticket from Zurich to Mulhouse, you will only need the relevant seat reservation for the Interrail segment