Google is your friend:

http://www.airfarewatchdog.com/blog/...-off-the-hook/

It appears that JetBlue is in the minority in not offering refunds for 24 hours.

Don't take this article as gospel. For example, Southwest does accept online cancellations and you can request and get a refund that way.

Not officially; however most people's experience is that they will 'make an exception' if it's less than 4 hours.

This is my understanding, when a reservation is cancelled within 24 hours of booking, a JetBlue credit will be issued in the full amount minus a $100 processing fee for cancellation.

Wirelessly posted (BlackBerry9630/5.0.0.591 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/105)

Can't you get that at any point? The change fee is the same $100 you are losing.

I literally just dealt with this last week. I bought a o/w ticket JFK-BOS for a mtg at 10p Friday night. Was told Saturday that I was given incorrect information and that the mtg was actually a different day than the one I had booked my ticket for. So I called Jetblue. (This was now about 12 hours after I bought the ticket.) After selecting the tel option to change an existing reservation I got an agent who said that Jetblue's policy is to offer refunds within 4 hours of ticking if a mistake was made (i.e. booked Jan 12 instead of Feb 12). I asked if an exception could be made seeing as most other airlines I've dealt with offer a 24 hour window. She put me on hold to speak with a supervisor. When she returned, she said "no, our window for refunds is 4 hours." Perhaps others have had different experience but AFIK this is Jetblue's policy.

Thanks everyone for the info.

In my opinion this is bad policy for Jetblue. I'm sure there are lots of others like me that would like this, not only for mistakes -- yes I do that every once in a while, but also because I often will book tickets when I find good deals then get work approval. I need that 24 hour window in case it's not approved.

Try booking thru orbitz
 

I believe if you book thru orbitz then you can cancel within 24 hours. (Double check with them ) .

I agree. It seems 4 hours is for the immediate realization you made a mistake. But most of my mistakes have been made when up late and then discovered only the next day.

I'm holding off on a purchase right now because of this. JetBlue lurkers, any purchase deferred is a possibility for rethinking my plans -- and considering the competition.

Has there been any change in this policy? I believe they need to implement this by Jan 24, 2012 to comply with the new federal rules:
http://www.airportavenger.com/_the_new_rules.html

24 hour rule
 

When they implement this change , I hope they don't eliminate giving of credits when the fare has gone down. This comes in really handy. (I am taking advantage of this now ) .