Twitter has a relatively new feature that allows you to remove a follower. The user won't receive a notification, but unless you block them, they'll be able to follow you again if they realize you've booted them.
The "Remove this follower" feature isn't available on the iOS and Android app, but it can be done when you visit Twitter using a computer's web browser.
How to remove a follower on Twitter
- Open the Twitter app in any web browser.
- Navigate to the account of the person you want to remove.
- Select More (the three horizontal dots).
- Select Remove this follower.
- Click Remove to confirm, and the person will be removed from your followers list.
How to soft block a user on the mobile app
If you want to use the app on your phone to block someone, there is a way to do it. It's called a soft block, and it entails blocking a user and quickly unblocking them so they automatically unfollow you.
- Open Twitter and tap your profile picture.
- From the dropdown menu, tap Profile, which will take you to your profile.
- Tap Followers and select the profile you want to block.
- Tap the three dots in the upper right corner of the screen.
- From the dropdown menu, find the people you don't want following you, select Block (username), then use the same method to unblock them. The user will no be blocked and they'll no longer be following you.