Can you notify Twitter contacts or groups about your username change?

On Twitter, there isn't a direct feature to notify all your contacts or groups about a username change in a single action. However, you can inform your followers and contacts about your username change using the following methods:

1. **Tweet Announcement**: Create a tweet announcing your username change. You can briefly explain the reason for the change and include your new username. Pinning this tweet to the top of your profile can help ensure it's seen by anyone visiting your profile.

2. **Direct Messages**: Send direct messages to individual followers or groups of followers to notify them about your username change. This approach is more personal and allows you to explain the change directly to specific contacts.

3. **Reply to Mentions**: When followers mention your old username in tweets or replies, respond to them with your new username. This helps correct any confusion and informs them about your updated handle.

4. **Retweet or Share**: If you have a significant following or presence on Twitter, consider retweeting or sharing your username change announcement periodically to ensure maximum visibility.

5. **Update Bio and Profile**: Update your profile bio to include a brief note about your username change. This serves as a permanent notification for new visitors to your profile.

6. **Cross-Promotion**: If you have accounts on other social media platforms, such as Instagram or Facebook, use those channels to notify your followers there as well. This can help reach a broader audience who may not be as active on Twitter.

While Twitter doesn't offer a direct mass notification feature for username changes, using these methods can effectively notify your followers and contacts about the update. This ensures that they can continue to interact with and mention your profile using your new username.