This will be available in the next few months according to our server owners. Please understand that ECC relies on stability and safety of the user base.
I believe that two things will have to happen before name changes are available here:
1 - All plug-ins will have to fully support the name change.
2 - A stable database to track name changes in order to protect from scamming and hacking.
Players that change their username are able to access the server - it is only if you change it after joining ECC that you are unable to change your name. It is well advertized here not to change your username at this time if you wish to continue play here.

 

This wont be supported for awhile. When you log in there is a notice telling you not to change your name.

 

I am against user name changes in general, not only on ECC. Why?

Look at the current situation. You know the usernames of people you are friends with/have an open deal with. If they changed their name, the only way to find their new nick would be by putting much effort into using various Mojang APIs to first find the UUID the user had before and then finsing out what their new name is. In order to at least speed up this process by a little, you would need to memorize their UUID. Yay, an incredibly long and hard to learn code. The alternative is to regularly check whether all your friends/contract partners still have the same name or whether they changed it, and then we'd also need 100% of the plugins to be name-independent. Yay.

 

Most servers don't do this because it is impossible to do with all the plugins. If you read the news posts about this they said around 9 months until they could probably actually try to do it if they wanted.

Mod should lock this as the suggestion is impossible to do

 

As @AdmiralD has already mentioned, user name changes could be potentially catastrophic for ECC if they are done not correctly, even if done well actually to be fair. As an economy server, a player's reputation is vital to helping to prevent scamming etc. Similarly, it would be a nightmare to keep track of who is who etc, this is especially relevant for staff for whom it would be harder to track warnings/player history/ban etc. Think about all of the in-game agreements that players have made with what would soon be 'old-names', which would require additional work each time evidence was presented to track down who is who.

Overall, name changes will just make everyone's lives a lot more complicated and could potentially lead to increased scamming/rule breaking.

It is worth reading this announcement: http://www.ecocitycraft.com/forum/threads/minecraft-usernames.116154/

As we have no plans for allowing name changes at this time, I will lock this.