"Your credit will become inactive in... days. You don't seem to have used any of your Skype Credit in a while. It becomes inactive if you haven't used it in 180 days. But don't worry - once it becomes inactive, you can reactivate it whenever you're ready to use it. Simply sign into your account online and follow the option to Reactivate credit."
Why does Skype credit need to become inactive? How long can it stay inactive before you lose it?
What happens when you reactivate your credit? Can it expire?