"senior TGV fares"
 

been checking out schedules for CDG to Les Arcs or Nice for later this summer. When it comes to "other criteria", I put in that we are Seniors for that fare which we are. When I see the details, it says we need a "valid Carte Senior" to show on the train.

what is this carte and to get?

booked under senior a couple of times and never had a problem on the train!

I may be mistaken, but I think the Carte Senior is for French citizens.

"the Carte Senior is for French citizens"

Obviously not the case. France is in the EU, and this is the twenty first century.

Cartes Seniors routinely cost €57 per person per year and can be bought online from the SNCF site. No limitation on country of residence. Self evidently no citizenship restriction.

It is a bit confusing : there are senior fares on some trains at some dates - usually not during peak times -.
Then there is the "carte senior". As Flanner says, you buy it from SNCF. You are guaranteed a discount (minimum 25% up to 50%) on ALL trains at ALL dates. The conductors ALWAYS check your ticket AGAINST the Senior Card.

The tickets you booked belong to the first category (occasional senior fares). You would not have been able to get the Senior Card ones without giving a card number.

I went back and tried a certain train - I put in that we were over 60 on the Who's Traveling area but used excursion fare - 200E came up as the fare for 2.

I then put in Senior fare and the fare was 150E

It looks like this is the only way to get a senior discount but not available to us as US citizens

something I am missing?

While in agreement with the bulk of what Pvoyageuse writes, I believe it is indeed possible to purchase tickets at the Carte Senior rate by simply selecting, under <i>qui participe a ce voyage</i>, age 60+ and, selecting Carte Senior under <i>Carte et Abonnement</i>.

If this is what you did, your tickets are invalid without purchasing and presenting a Carte Abonnement to the conductor. Luckily, if you need a Carte Abonnement, the SNCF is selling a limited number at the reduced price of 40€ rather than the normal 57€.

<i>something I am missing?</i>

Very likely. There is no citizenship requirement for purchasing and using a Carte Senior. What website are you using dsevig?

Right Sarastro - I am using an S'miles card on top of my Senior card - this is why I always have to give the card number.
Anyway if the OP purchased a senior fare ticket without a Senior card, she must either buy one or face trouble (and a fine) when the conductor checks it. They always do. She can also change her ticket, it should not be a problem, senior tickets are refundable.