After booking a flight on Priceline, can you log onto the airline's website and change your seat assignment?

Usually you can but it really depends on the fare class you purchase, which Priceline doesn't show you till after you've made the purchase. Within each service level (economy/coach, business, first) there are several fare classes also called fare buckets. Sometimes Priceline and the other discounters get tickets from very restricted fare buckets that won't let you even change seats. Usually what you get from Priceline isn't quite that heavily restricted but sometimes it can be. As for the poster who said you can switch to first class for free just if the seats are empty on the day of travel, that's pretty unlikely, but most airlines will sell you a cheap upgrade to first class ($50-250 depending on how far you are travelling) 24 hours before the flight, depending on how full first class is. This too is an exception and not an every-day occurance as airlines will give their frequent fliers free first class upgrades before the general public gets the chance at the discount upgrades.After booking a flight on Priceline, can you log onto the airline's website and change your seat assignment?Someone recently told me that if you wait until the last 24-36 hours and change your seat to First Class, they will do it at the same price. Do it any sooner and you will pay first class prices. This actually came from a trustworthy source. Someone whom I work with and flies a LOT. She uses this trick. But.....I live in Wilmington, NC. This could make a difference depepnding on where you live. I say it's worth calling and asking. Don't do it online just to ensure you're not being screwed on this. Good Luck!!