Train fares in Europe and UK

Almost always for long-distance journeys. If you book in advance (often 90 days, but some routes put cheap tickets on sale even earlier), you will get very significant discounts. Fares will never go down closer to the date of travel.

One disadvantage of buying discount advance tickets, though, is that you are usually booked only on one specific journey. If you miss a train, you will often have to book a new full-price fare, so it can be a bad idea to get a discount ticket if you are travelling immediately after making a long-distance flight.

There is usually no advance discount for local journeys.

so in essence no need to advance book for venice-rome trip but must for paris-zurich trip

so in essence no need to advance book for venice-rome

I can't imagine why you wouldn't. You can get tickets as low as €19. Why would you want to pay 4 times that much?

For your Paris - Zürich you have highlighted a special case.
Each country (or more correctly each railway company) has slightly different rules.

• Swiss railways (along with Belgium and the Netherlands for internal trains) do not vary the price depending on when you buy the ticket. There is no advantage in advance purcahse, and all tickets are valid on nay train.
• For French railways, TGV trains you must book. If you want to buy on the day (and pay maximum price), you still get a seat allocated. Same applies to Italy.

So the same train is "fixed price, no booking" from Zürich to Basel, and "variable price booking required" from Basel to Paris.

For some other countries (UK, Germany), you can either book a cheap ticket in advance with a seat allocated on a specific train, or book a more expensive open ticket without reservation on the day, and then you have to find a free seat.

Paris-Zurich can be had occasionally for as low as 25 euro booked 3 to 4 months in advance nonrefundable. More often at 39 or 49 euro, and usually 79 euro on Sundays. The full fare price is 140 euro.

Prices do not increase closer to the date of journey, but the discounted fares are bought up far in advance so that only the full fares are left.

Advance purchase discounts are available for train tickets in most of western Europe, if you're ready to lock in travel dates and times. These tickets are not refundable and often not changeable. Most go on sale 2 - 3 months in advance of the travel date, which is when the lowest rates are offered, with limited seats at those prices. See more at Buying Tickets and on the single-country pages in our rail travel section. Meanwhile, maps throughout this site show you full-fare 2nd class ticket prices for selected routes.

It's easier to compare the value of a rail pass if you have a firm route plan. You'll also need to know the Seat Reservation requirements. Direct Paris to Switzerland TGV trains have the most restrictive reservation availability for pass holders and one of the highest seat reservation prices; it's cheaper to reserve the TGV to Strasbourg, near the border, and make a connection there, but still wise to reserve 1-3 months in advance; many rail pass agents can process that at the same time that you buy a pass; if booking from India, see www.raileurope-world.com. For your routes outside of France, other reservations can be made on shorter notice and are often optional. Most rail passes will cover your kids for free if they are age 11 or younger.

BritRail passes are separate from other rail passes. If you only need one train ride from London to Edinburgh, then you would not particularly need a pass, but would save money by booking that ticket in advance at www.nationalrail.co.uk. Free kids on the BritRail pass can be as old as 15.