Originally Posted by
emcampbe
SDC is basically a waiver of the change fee, though fare difference still applies. As long as there is Y>0 on the flight one wants to change to, and is within the time limitations (within 24 hours of both current and new floghts), gold or above can SDC for free. Any additional $ needed is a fare difference, which really applies for any change. SDC itself is still free.
I know this, and you know this, but it really, really complicates things, so I intentionally left it out.
Originally Posted by
emcampbe
The app/site will only show options without a fare difference, but any gold or higher can SDC into a higher fare bucket by calling an agent and paying the fare difference. SDC remains free.
Yes, that's true, but when people are asking about SDC, they normally mean no-fare-difference SDC.