How flexible is 'fully flexible'?

Evening all,

Subject says it all really - if I have a J,W or Y ticket what are my options around changing the flight date?

Specifically, how much notice do I have to give and is there a charge?

Thanks in advance!

Mat

Also...while I think of it...

Is there a restriction on the number of times I can change the date or by how far in the future?

In my experience with W fares, you can change as often as you like to any date within a few days of departure so long as there are seats. I have bought W fares and keep them for when I need them, bumping them 6 months into the future if I haven't used them. You can change up to the moment of departure. The only thing I have found very disatisfactory is getting refunds. The ticket is fully refundable but the process of getting a refund is slow and a hassle. You have to fill in forms and send them off. In my case it took several months to receive the refund which I thought was very poor. I had to pay a premium to change a date once when the fuel surcharge went up. Other than that fully flexible means you can go anytime you like. That's why they are so expensive. IMV they are not worth it, the charges for changing dates on lesser flexible fares are manageable and usually you only need one or two changes.

You are free to change, but IIRC there is some requirement to travel within 12-ish months of the date of the original booking ... And as worc0670 says, you can get hit by changes in fees and taxes when you defer.