When I logged into Audible today there was a notice:
"News about your credits
You can now keep your credits for up to a year."
They are spinning it like it's a good thing, but for me it may not be.
Clicking on the link takes you to
this Help page.
To me it sounds like they are closing another loophole by eliminating the ability to rollover credits. Starting today, all credits will be good for 12 months only, and then expire (they will continue to be forfeit if you cancel your membership).
Note: credits "issued" before today will be treated differently, see the link for details.
In the past I have purchased an annual plan and then switched to a Listener Light at the end of the year, to give me 2 years to use the credits. It looks like this will no longer be possible once I have used my current credits.
Pretty much the only reason I stick with Audible now days is for their exclusive content. In the future, I may have to stockpile the exclusive items I need to purchase with credits until I have enough to make it worth it the membership, and then cancel until I have enough again.