You may be able to buy your Turkish train ticket just before travel, but it's wise to reserve your place(s) at least a day or two in advance if possible.
During holiday times, it's essential to reserve in advance in order to secure the seat or compartment on the train you prefer.
Please note: train seat and sleeping-car berth reservations may be made no more than 30 days in advance, andtickets must be issued and paid for at the time of reservation. In other words, you can't reserve your seat or sleeping compartment more than two weeks in advance, and you must pay in full when you reserve your seat(s) or bed(s) on the train.
For sleeping cars, I'd recommend reserving at least several days in advance if possible. If you can reserve a week or two in advance, do it, just to be sure.
Make a Reservation...or Not
Making a reservation or purchasing a ticket on the Turkish State Railways website using the EYBİS computerized reservation system is a bit chancy, but may work if you're lucky.
There are TCDD apps for Apple iPhones and Android phones, but so far they are only in Turkish.
EYBİS
The Turkish State Railways's EYBİS Tickets websiteReservation and Ticket Purchase functions have an English-language section that is mostly in English, with a few Turkish labels which I'll mention below.
1. On the EYBİS Tickets website homepage, I could not get the train or ticket information for high-speed trains (YHT).
For Traditional trains, select "Sales" if you wish to make a reservation and purchase a ticket; or "Booking" if you wish to make only a reservation.
Select either "One Way" [Single] or "Return" [Round-Trip].
Input the names of your origin and destination cities using only the correct spelling in Turkish characters. (For example, if you enter "Izmir," without the initial dotted capital-I, instead of "İzmir," nothing will happen.)
You also need to know the correct departure station if the city has more than one station. For example, if you select "İzmir (Basmane)" as your departure, and "Eskişehir" for arrival, you will see the schedule for the İzmir Mavi Tren. If you select "İzmir (Alsancak),"you will see "No travel solution found."
You lost the computer game! Start over!
2. Click in the Departure Date field, and a calendar will drop down...in Turkish. Do you know the Turkish Days of the Week and Months of the Year? If not, you can learn them here.
Select the Number of Passenger, then click Search.
3. The next screens, for reserving your seat, are pretty easy to follow. The departure and arrival dates and time, and the journey duration are given, as well as the train name.
Coach type: there may be only one type, such as Pulman (the coach-type names are all Turkish only. I've put a list of Train Terms on this page.)
4. For personal information, enter Name and Surname for each passenger.
You do not need to enter a TC Identification No. (This is something only Turkish citizens have.)
As for Gender, Turkish tradition dictates that unaccompanied females not be seated next to un-acquainted males, so the computer will try to sort this out for you. The choices are "Man" and "Woman."
Tariff is the fare. TAM means "Full Fare," which is probably what you'll be paying, although the drop-down list offers also 65 Yaş %50, a 50% discount for those aged 65 and over; GENÇ (Youth); and YAŞLI (Senior aged 60 to 64, 20% discount). You probably don't qualify for the other fares.
Special services is if you want sleeping accommodations, etc. (In a sleeping car, Üst is the upper berth, Alt is the lower.)
Enter the rest of the information, including or your mobile phone (only Turkish phone numbers are allowed) and/or email address, then proceed to the payment screen and fill in your credit card information.
The Easier Way to Buy a Ticket
You can buy train tickets at many train stations from a ticket agent or a Trenmatik ticket machine; at an authorized Turkish post office (PTT); or from a good travel agency.
Contact my friends at Efendi Travel in Istanbul who will be happy to make the train reservation for you, and for any other travel services you may need. More...
It's a good idea to also use these full-service travel agencies for your other travel arrangements in Turkey: hotels, tours, cruises, car rentals, guides, etc.
The prices you pay to an agency may be somewhat higher than the published fares to compensate the agency for its work in making your reservations and issuing your tickets. (Selling train tickets is not really a profitable business.)
Pick Up Your Ticket Where You Bought It!
Note that you must pick up your tickets from the office through which you bought them. Unfortunately, you cannot make a reservation through an agency and then pick up your ticket(s) at the train station (at least not yet).
Finally, travel agencies are not authorized to write international train tickets (for travel from Turkey to other countries). International tickets must be written by Turkish State Railways. However, an agency may agree to pay for and pick up your ticket in exchange for a service fee(particularly if you are ordering other travel services from the agency at the same time). The service fee is necessary because the agency must actually send a staff member to the railroad station to buy your tickets in your place.
Best Travel Agencies 