Al,
This came up here a little while ago.
As per the GAR form
3. AT PRIVATE AIRFIELDS AND HELIPADS YOU CAN ONLY FLY TO AND FROM OTHER EU
COUNTRIES, UNLESS YOU HAVE AN AGREEMENT TO DO SO. IN PARTICULAR,
FLIGHTS TO/FROM THE CHANNEL ISLANDS WILL NEED TO BE AGREED WITH
CUSTOMS AND POLICE.
THE NOTIFICATION PERIOD IS THE SAME AS FOR GAA AIRFIELDS
As the Channel Islands are not an EU destination, you can not fly to them from a private field without AGREEMENT from Customs. You'll have to go from either a Customs/SB designated airport, or from a GAA aerodrome.
dp