Flight Plan filing
Please be wary of addressing flight plans.
If the flight is IFR wholly within IFPS Zone then its straightforward, but please check for VFR plans and anything going outside the IFPS especially transatlantic flights. If you modify an existing plan then IFPS will send any changes to the original addressees.
IIRC UK CAP550 contains the information on additional addresses.
I note that your location is Iceland so maybe your CAA has a similar document.
Hope this helps.