Why can I not cancel health policy with a month’s notice?

You are thinking of the Loi Hamon, which allows you to cancel certain kinds of insurance with just a month’s notice after the end of the first year, however this applies mainly to car and home insurance, not health top-up policies.

Health policies still fall under the old rules relating to cancellation before the annual renewal date, known as the date d’échéance. Note that this is not always the date when you took the contract out (date d’anniversaire) – some firms automatically move the date to January 1 while others move it to the end of the quarter in which you signed up.

To cancel at the renewal date you need to respect a certain notice period (date limite de résiliation) specified in the contract, which is usually one or two months.

It is best to cancel using a lettre recommandée avec avis de reception (recorded delivery with reception note).

There are some exceptions where you may cancel with a month’s notice, notably if you are stopping because you have to join a work mutuelle or because of a change in your situation such as moving house, getting married, retiring or changing job. The latter only applies, however, if the change in situation affects your risks for insurance purposes.

Under certain conditions (see your contract) you may also be able to cancel at short notice if there is an unexpected rise in the insurance cost.