iOS 8 Voicemails work pretty much the same way as in iOS 7. And since not much has changed, deleting voicemails is almost similar to how you do it in the previous iOS.
Your iPhone not only stores the voicemails you receive but it also stores deleted voice mails, which adds up to the used-space on the iPhone. For this reason, it's not just enough to delete the voicemail from the Voicemail menu in the Phone app. You need to clear them out completely. If you're looking to delete voicemail on your iPhone, here's what you need to do:
How to delete voicemails from your iPhone in iOS 8 on iPhone:
(Note that you can't delete all voicemails simultaneously or at once)
- Open the Phone app
- Tap on Voicemail menu from the bottom
- Swipe left on the voicemail you want to delete. Then tap on Delete.
The above method deletes voicemails from the Phone app but it doesn't really clear it out from your iPhone. Instead, it puts them into a recycle bin/trash where it can be recovered from. This means the deleted voicemails will still be occupying space on your iPhone.
- Once you're done deleting voicemail from this list, scroll to the bottom of the Voicemail list. You should see a Deleted option. Tap on this.
- This list shows all deleted voicemails that are still recoverable. (kind of a recycle bin / trash)
- You should see a Clear All option on top. Tap this and all deleted voicemails will be cleared.
Sometimes, you'll notice that the Clear All is disabled (or grayed out). In this case, you can try a few of the following solutions:
- Manually clear out a few deleted voicemails because sometimes, a lot of voicemails can cause processing issues.
- Reset network settings from Settings → General → Reset
- Try clearing out all voicemail from your account with your carrier's website.