Buying RER tickets on Eurostar to Paris

The Eurostar website only suggests you need to buy these when you get there I am afraid, looks like the option to buy them before hand is no longer being provided. There does not seem to be an option to buy them online either.

Oui, c'est possible.

Thanks so much for your response.
In fact, we WERE able to buy the tickets on the Eurostar train, which was a huge relief as we had such little time to spare. We bought two extra for the return journey- which is in 2 days time - we’re in Nice at the moment.
Apparently, they used to be on sale from a machine at St Pancras - but this was stopped after Brexit.

Glad you managed to.
By the way, if anyone needs to know, you can also buy Oyster cards on Eurostar.
I hope Nice is sunny. Brittany is cooling down, and rain is expected from here on.

I'm very late to this thread, BUT --- for ALL things re trains, especially Europe but even worldwide now, DO SEE the wonderful Man in Seat61 website. www.seat61.com

Masses of great advice, suggested routes, ticketing, even handy hotels and cafes. Oh, and loads of pics and films.

His latest piece was re the new Nightjet trains (sleepers) which have increased those routes across Europe.

This page refers to crossing Paris, and includes tips re various tickets! www.seat61.com/changing-stations-in-paris.htm

It’s a great site DrWatson my first port of call for train journey’s.

Thanks for that, DrWatson. I’ve noted it for next time !