RailEurope charges a lot of fees ...Need ticket from Geneva to Paris to London

Book with SNCF: www.sncf-connect.com
And book this in just one transaction, ie. book Geneva - London. The system will figure out how much is needed for the layover for you.
However, in your place I would just fly to London. There should be plenty of flights to choose from.

British Airways has flights from Geneva to Heathrow that day for 92-126 CHF. That is going to be a lot simpler and cheaper than the two trains. Just the Eurostar train from Paris to London will cost you $113-$139 for an afternoon train.

There are TGV's from Geneva to Paris Gare de Lyon every 2 hours starting at 6:29 am (sometimes at 29 past the even hours, sometimes at 24 past the even hours), and they all arrive at 42 past 3 hours later. Eurostar departures are every hour with some variation in exact departure times.

All of these vary in price depending on departure times for nonrefundable tickets purchased now. I am looking at www.sbb.ch/en and www.eurostar.com, but all are available.

Since it appears that all of these will cost you in excess of $200 pp (after my rough currency conversion), consider flying from Geneva to London. Swiss and BA fly to Heathrow for about the same price. There is also Easyjet to Gatwick, Luton, or Stanstead for about $120 pp with full luggage and front seat selection.

SNCF connect have a train every 2 hours, with an overall journey time of 7 hours.

However I would not be happy booking that as a through ticket because Eurostar say it is a 90 minute check in time, but SNCF only allow a 90 minute connection time including the train across Paris with the statement-

Accueil embarquement : avec votre passeport jusqu'à 30 minutes avant le départ pour un voyage en Angleterre

(which does not correspond) so ideally you want the 0824 from Geneva arrive Paris Gare de Lyon at 1142.- 54 Euro each

However the 1512 and 1657 Eurostar are both £104 each and the 1608 is £114.

Between Gare de Lyon and Nord take RER Line D northbound for 2 stops.

Thank you for such quick responses.

Yes. though we wanted to experience the train ride and see some countryside, we may opt to fly.

Thank you much

For that distance, and the time involved including the check in procedures for the Eurostar, my suggestion would be to fly.

I understand wanting the experience and if time and money are not a big concern, I would book Geneva to Paris Gare de Lyon through SNCF or SBB If it were me, I would spend a night in Paris. Enjoy a nice meal and a stroll, then schedule yourself on the Eurostar, which leaves only out of Gare du Nord. You need to arrive 90 minutes before the Eurostar departs to check in. Book the Eurostar on the official site. No need for Trainline or Rail Europe.

It is time consuming and more expensive than flying, but a night in Paris as a “layover” is quite nice and if you love trains, it is not just transportation, it is a journey. It is what we would do, in fact, time permitting.

Yes. though we wanted to experience the train ride and see some
countryside, we may opt to fly.

If you want to experience a train ride Eurostar is the worst choice. Eurostar is basically an attempt at "lets make something that is as inconvenient and annoying as plane travel, but slower." If you want a real train ride there are plenty of those in Switzerland.

I've given up on Eurostar. I fly to the UK. If would even fly Paris - London. If you have to be there 90 minutes before departure than you are a failure as a railways. (In fact, the moment you make me queue up to board a train you are doing it wrong).

Easyjet has 6 flights that day from Geneva to London Gatwick and two to London Luton for between 31.45 and 65.95 CHF, before baggage fees of 62.44 for a hold bag or 75.90 for a large cabin bag.

Re @Wengen K's comments, he repeats this comment at regular intervals. The train is still faster than air from Paris to London city centre to city centre. And passport and security checks are a fact of life. Travelling east from Switzerland out of Schengen passport checks are a fact of life- they just normally happen on the train while the train is stationary- but the same effect.

They have to happen. Outside the bubble of Switzerland terrorism is a fact of life. It is a small price to pay to have the reassurance that the train is not going to be blown up in the tunnel.

It is NOT a failure of the railway. In an ideal world Eurostar would doubtless not want to have to do that, but we live in the real world

I still would choose Eurostar to exit London for the Continent, as it gets you to the city center in Brussels, Amsterdam and Paris. But I understand the frustration. It's much worse departing from Paris than it is from London.

Re @Wengen K's comments, he repeats this comment at regular intervals

Yes. I do that, because it saddens me immensely that after decades the Channel tunnel is still not nearly as successful is it was hoped. We were going to have trains from Geneva to London, from Brussels to Birmingham, from Cologne to Glasgow.

None of that materialised, because of the passport and security checks, Eurostar now wants you to be at the station 90 minutes before departure. And people consider that reasonable.
It is not.

Before we had Schengen passport control on cross border trains was done on the train, while the train was moving. And it was at one time considered to do that on Eurostar as well. As to the security controls: These are completely superfluous. They do not make travel safer, just less convenient. (and that applies to the security theatre at the airports as well...)

There are Youtube videos about the Eurostar experience, watch a few (make sure they are current).

And for train travel the Man in Seat 61 is going to have all the answers. He also recommends Trainline, FWIW.

The failure of the Regional Eurostars and of Nightstar to appear has little or nothing to do with security and passport checks.

It was primarily due to the poor passenger figures originally on the main services to Paris and Amsterdam, and to doubts over the economic viability of such trains, as it would have been very difficult for them to use the then Eurostar terminal in London at Waterloo International.

I have to disagree here.

What killed the regional Eurostars is that because of security requirements and passport controls cabotage would not be possible. That is well know. Long distance trains in Europe typically do not live of end-to-end traffic. But if you can't mix local and international travelers on the same train such services become impossible.

Eurostar now wants you to be at the station 90 minutes before departure. And people consider that reasonable.

It is not.

I find it eminently reasonable. And anyway, my last trip to London and back, the guidance from Eurostar was to be there 45-60 minutes departing Paris, and 60-90 minutes departing London. In other words, even Eurostar itself (which is protecting its self-interest of having you be able to take the train you have paid for and reserved) doesn't advise you to be there 90 minutes ahead of time in all cases. I didn't go 90 minutes ahead in either case, and I had plenty of time.

Ninety minutes is a red herring. And the Eurostar is by far the most convenient way of going city center to city center without the hassle of hauling one's butt out to the airport and back, packing according to strict airline and civil aviation authority requirements, separating liquids (and only bringing small quantities in a quart-sized bag, etc)..

Not to mention it's substantially better for the environment. Airline tickets are artificially cheap, which is an unfortunate dissuasive decision our policymakers have made. But trashing Eurostar as inconvenient really misses the mark.

Trains are better for the environment, yes. Which is why it is such a pity that we cannot have trains from Geneva, Zurich or Basel, or Frankfurt to London, or from Paris to Glasgow or Brussels to Birmingham, only because of irrational paranoia. It really saddens me.