How to change usernames on Instagram (Social Media)
*Update (20 Sept 2015): Instagram has updated their app and now username changes are linked to all your previous tags and mentions. It is no longer crucial to follow the practice below; but it is still handy.
At some point in your social media "career" you may want to change your username on Instagram (or any other social media platform). Be it a sign of growing up, a change of branding strategy or simply because your dream username has finally been free'd up. Whatever the case, you should always follow SMO (Social Media Optimisation) best practice on this process because it is very important.
You'll want to make your username change as well advertised, seamless and easy as possible for your friends and followers. If for any reason, someone searching for you can't find you under your old username, you have failed, and they will move on without a second thought.
Social Media username change best practice:
Change your primary account (your account with all your followers) to the new username as quickly as possible. You'll want to try and grab the username on as many platforms and mediums as possible (Twitter, Pinterest even email accounts).
Make a secondary Instagram account under your old username. This account should be temporary and act only as a redirection account.
On this new, temporary account with your old username, change the profile description to inform users that you have moved to a new account and username.
Make a single post stating that you have moved and make sure to mention & tag your new username.
Why is this important?
All the hard work, time and effort you have previously put in for your old account will have been wasted if you don't. Everywhere that you are tagged and all the collaborations and mentions you have built up with your old username will be wasted because they will be linked to a dead account (see image above: user not found).
By creating a temporary redirection account, you will ensure that people can continue to find you with ease. After a while, you may decide to close the redirection account, which is fine, but really, it isn't costing you anything to keep it open.
Of course this only really applies to those who have put in a significant amount of effort into their old usernames. Hope this guide has helped!