Seat selection when using online booking sites

If you are unable to pick your seat using your confirmation code on the airline's website, you can always call the airline and pick your seat with them. Some airlines, such as Southwest Airlines in the US, don't offer pre-selected seats. I have booked Alaskan Airline flights through American Airlines (since they are partner airlines) and have been able to go to Alaska Airlines and finalize my seating choices. I have also booked flights through Expedia and have gotten a confirmation code to look up my flight into and finalize my seats.

Couple of things:

• If the fare code allows seat selection, either included or with a fee, then yes, 90% of the time, you can use the Reservation Number/Record Locator to look up the reservation on the airline's web site and also add it to you profile.
• Once you do that, you can then select the seats.
• Some airlines, such as American, show mostly up to date seat maps on their site without having to start a purchase. If that's not available, you can always begin a reservation, then just not complete it.
• If you end up purchasing a fare that does not allow seat selection, you still have 24 hours to cancel (double check the options first).

There is no general answer to your question.

It really depends on the site. Only a few allow to select seats at the time of booking and before actually purchasing the ticket. Not only that, it depends on the airline and flight.

Once you have purchased the ticket though you should get almost immediately a Booking Reference (6-char alpha-numeric code) that you can use most times on the airline's website in order to select a seat or at least check the seat assignment.

Keep in mind that some fares charge a fee for seat selection and others do not allow seat selection at all. Most times though, you can select a seat. It is also possible to select a seat sometimes using the site of a partner airline. This is important to know if you have a flight operated by multiple airlines as sometimes one website will not let you select the seat and another will (this happened to me earlier this year with multiple Star-Alliance airlines). In only one case I was unable to select a seat online.

You need to check very carefully the terms of the fare you are booking on the third party site. Sometimes, it is cheap because it does not allow seat selection (or only allows it within a restricted time frame, like 24 hours before the flight; and if you have to pay, it is for each segment).

The only way you would know this is to look at the terms of the fare or the terms of the site you are booking from - there is no universal answer.

If you have already booked, the only way to know what the terms of your fare are, is to look it up at the airline. You can do this (as other's mentioned) by going to the airline's "manage a reservation" or similar section, entering the last name and the reservation code - sometimes called PNR. This is often different than the reference code for the booking that is generated on that site.

Only the airline can tell you definitively if seats can be reserved, and how to go about it (online, at the desk, paying a fee, complimentary, etc.)