Quote Originally Posted by worldofneil View Post
Sorry, but no it doesn't. I thought that for a long time too, but all it does is disable the service account so that it can't be used from within the game. It essentially is a "on hold" toggle. Yes I do mean toggle, because you can click it again at anytime to reactivate it. If you disable/cancel the service account it stops it from appearing in game when you go to switch between service accounts (only applicable if you have multiple service accounts).

I appreciate that probably doesn't sound very useful, but it's very useful for hiding service accounts that don't have subscriptions so you can't accidentality select them. Selecting the wrong one might also not sound like a big deal, but because of the how the game works if you select a service account that doesn't have a subscription it comes up with an error and exits the entire game, forcing you to start over and log back in again and since they're all labelled the same (Final Fantasy XIV 1, Final Fantasy XIV 2, Final Fantasy XIV 3, etc...) it's easy to get them mixed up. This way you can choose to just hide inactive accounts.

Hope that helps to explain!
There is an option to delete your entire Square Enix account though, not just cancel your service account for FFXIV. From what I can see though, deletion of the entire SE account IS permanent.