Numero fiscal

Hi everyone,
Does anyone know in their collective wisdom, is your numero fiscal confidential or not. I have a client who has asked for it and I am reluctant to give out information I feel is personal.
They already have my SIRET number etc and I feel that is enough for a business relationship, I am not TVA registered.
Thanks for anyone who can shed light on this.

Thanks for your answers, we have since worked out he probably means the TVA number, although we are not TVA registered. Fortunately this is on the invoices, along with the SIRET number so he has all the information he needs.
The reason he is asking is because he is an unhappy client and is threatening to report us to various authorities and to “tell my sad story on every website in France, England, and the USA”. Fortunately we are not too worried as we are confident we have done nothing wrong, however we just want to make sure we do everything correctly just in case he feels has a legal basis to bring a claim, however unjustified.
You know you sometimes have this feeling that a client is not working out…

Maybe it is different for a SARL, or I mistake it with the Numero TVA…

I don’t see why it should be confidential either, since it should a) be written somewhere in your mentions legales, and b) on your official company stamp.