Changed Twitter username. Still showing in Twitter searches

Question

If my Twitter handle were @johnsmith, and I were to change it to @johndoe, I'd expect that searches in the Twitter search input for the old username would now show no connection to the new name.

On the contrary, if I change my handle, wait a few days, and then search the old name, I see the many replies from other users tweeted to the old name, and some of these—but strangely not all—have the new name added to them now (they show as tweeted to both the old and new name, despite being dated before the new name existed).

Why would this be? Can it be avoided?

Answer 1

According to twitter's help center:

Note: Changing your username will not affect your existing followers, Direct Messages, or replies. Your followers will simply see a new username next to your profile photo when you update. We suggest you alert your followers before you change your username so they can direct replies or Direct Messages to your new username

This means that what you are experiencing normal and updating your username doesn't affect the replies you've received however you would see the update on your profile page and your profile url will change, from https://twitter.com/oldusername to https://twitter.com/newusername.

Answer 2

Twitter has a "deeper" reference called Twitter ID, which connects accounts with all the engagement related to them. Different from @username (handle) which can be changed, one can not change their Twitter ID.

The Twitter ID is not visible in the User Interface of Twitter, however, there are external services like gettwitterid.com which will give you the Twitter ID for any @username plugged-in.

To do the reverse and match a Twitter ID with its current @username you can use this URL:

https://twitter.com/intent/user?user_id={twitter_id}

Once you identify your Twitter ID you can test and see that no matter how many @username changes you do, your Twitter ID always remain the same. This is the reason why changing a @username does not affect previous engagements, followers and following counts.