Reader's Question—Channel Islands Customs procedures

France to the Channel Islands (Iles Anglo-Normandes)

I am keen to pop into the Channel Islands when flying France to the UK so I can pick up cheap fuel.

If someone could advise where to find the info on customs/immigration for that trip (and the opposite direction) I would like to know.

Alternatively:  How do I purchase duty free fuel when leaving France?

I will be flying HA-YAB which I wrote about in an earlier article.