My wife and I are over 65. we will be in Paris for about a year and we generally get a monthly Navigo pass. Is there some way we can get a senior discount? We are not French citizens - we just have a visa de long sejour.
Here is the page that explains how you can get half off if you sign up for an annual plan. and I am pretty sure you can only sign up for an annual (year-long) Navigo with a French bank account - but who knows, maybe things have changed.
The annual plan still gets billed monthly — but it gets billed automatically to your (French) bank account.
If you have all the other pieces in place, here is the page from the RATP website that tells what you need to qualify for the half-price annual senior card (with an application fee of €7.60).
The only discount that I know of for seniors is the Navigo Senior Annual Pass. Information about it is available at https://www.transilien.com/en/page-tarifs/navigo-senior#content-section-278-part-3-tab
Edit: Oops. Posting the same time as Kim and the info above is for the same thing as her post.