This cannot be true. I have multiple bank accounts in France and never had to do this.

It really depends on the bank, I had to change accounts as well when I was with Credit Agricole, but all is fine and dandy since I am with Boursorama

Well, Crédit Agricole is kind of a special case, at it was initially for farmers and the like (which do not usually move), and has a heavy reliance on local branches. Although I remember my parents having an account there and not having that issue after moving on the other side of the country.

Yeah a recurring theme in this thread seems to be non french people getting caught in our public service vs private(ised) operator spectrum. As the saying goes "it's not a bug, it's a feature"!

Word of advice from an equally confused native: smile and ask questions. That ought to get you far enough unless you're in Paris (my condolences if you have to deal with the ile de france préfectures or mairies).

A département is not a suburb within a city - it's a large region of France, equivalent to a county in the UK, except with a totally different administrative setup.

That's true, but there is the special case of Paris, which is itself a département and has its suburbs (depending on how strictly you define the term) stretching over three to seven different départements. If you move within the Paris metropolitan area, it's easy to change département even while staying in the suburbs of the same city.

Also, the large regions of France are called "régions" ;-)

Yes and you can be in a suburb of NYC and be in a different state!