Good question, I'd be interested to see the answers.

best thing woudl be to speak to Swisscom, or whomever you have a contract with...theyll most likely ask you to pay something.

Insurance you may get a refund, depends how you pay and how long notice you give..again speak to them.

medical...youre obliged to be covered to the day you leave, so tell em the leaving date, and theyll adjust the premium accordingly.

you will haveto speak to each contract issuer you have, tell em youre leaving switzerland "for good" and badabing...problem sorted.

Also dont forget your pension AVS pillar 2 and 3 if you have it...youre entitled to take all your Swiss contributions with you, and if you leave ex EU then its in cash... a nice leaving bonus.

good luck.

Ch

You may wish to contact your embassy's consular services department.  They may have a departure check-list. 

The Office Cantonal de la Population does have a form for departure, an attestation.  It can be useful for presenting to your health insurer.

Also, if you have any official document, such as permits, make sure you surrender them to the OCP, either in person or by registered mail. 

Thanks very much for your thoughts on this.

Cheers!

And don't forget to settle up with the taxes that you owe . . . after which the tax authorities will give you a certificate which you will need to terminate your work permit.  No need if you don't want to come back, but I'd leave that option open if I were you.