score:9
Yes, as long as you have a valid multiple entry Schengen visa, you can enter and exit the Schengen territory as many times as you want. Which in this case means you're allowed to fly from the UK to Finland. Of course, you need to have a separate visa for the UK if you need one.
Upvote:0
Your Schengen visa is valid for all Schengen countries, if you have the multiple entry visa you are allowed to enter/exit the Schengen area as you please for an accumulative period of a maximum of 90 days within a 180 day period.
and since you have a UK visa as well, you will have absolutely no problem at all with your Spain-UK-Finland routing.
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