Yep, its as simple as faxing it to ATC. They will then forward the plan to all those who need to know.
If you are planning to depart significantly later than the planned time, be sure to let ATC know and they will send a delay (DLA) message. Also, ask ATC to confirm the plan is activated and that it is deactivated at the end of the route (esp. in France - numerous articles in Pilot cover this, SAR being declared because the plan wasn't closed).
One thing to be careful of, make sure you have told Immigration and the Special Branch if you are going to the Isle of Man, I've never been but I believe it falls under the same rules as Jersey where you must clear Customs out and in and tell Special Branch. A call to your local customs man will help you find out the exact procedures. Customs will more than likely need a General Declaration, which has the names of all on board, along with date of birth and passport numbers, plus other details.
Edited to add more data.
