I had a problem with SB trying to fly from Sandown to CI once. I had filed from home but had to stop at Sandownd for an unexpected fuel stop. Re filed the flight plan and SB form. A PC from the SB unit down there phoned me and told me I could not do the flight as I had not given 12hrs notice. i pointed out that I had filed from home to CI and this was an unplanned stop. He was adamant that I could not go. Got the right hump when I told him to forget it and that I would go via Cherbourg.
I don't have any problems with coming and going from our place at Spanhoe and that is not listed as a designated port. Myabe Northants police are more enlightened!