Crossing from Northern Finland to Sweden

AFAIK, there’s no direct bus between Kemi and Lulea anymore, you need to change in Tornio/Haparanda.

The buses from Haparanda to Lulea are included in the Interrail/Eurail pass. But you can also travel by train on that stretch. No idea about the bus in Finland.

(You could even take the night train in the early morning from Kemi to Tornio-Itäinen and walk across the boarder. 90 minutes, nice walk on the Swedish side, less so on the Finnish side)

I got told last autumn that passenger rail between Sweden and Finland should start in April but I assume they postponed the start of these services again :(