Set Encoding of File to UTF8 With BOM in Sublime Text 3

Solution 1:

Into Preferences > Settings - Users
File : Preferences.sublime-settings

Write this :

"show_encoding" : true,

It's explain on the release note date 17 December 2013. Build 3059. Official site Sublime Text 3

Solution 2:

I can't set "UTF-8 with BOM" in the corner button either, but I can change it from the menu bar.

"File"->"Save with encoding"->"UTF-8 with BOM"

Solution 3:

Into the Preferences > Setting - Default

You will have the next by default:

// Display file encoding in the status bar
    "show_encoding": false

You could change it or like cdesmetz said set your user settings.