At Skype, we regularly release updates to our software so that we can introduce new features, improve existing ones and fix bugs.
Updating Skype is always free, and we recommend that you use the latest version of Skype, which is why Skype automatically updates to the latest version by default.
If you want to know what’s in the latest release, you can find out What's New for mobile and desktop.
From time to time we retire older versions of Skype. When this happens, you won't be able to sign in until you upgrade to the latest version.
What happens to my Skype Credit or subscriptions when I upgrade?
Updating Skype to the latest version does not affect your Skype Credit balance or subscriptions. Any products you've purchased remain in your account and available to use just as they were before the upgrade.