We provide logo files with transparent backgrounds in the Premium logo-only package, as well as in our Brand Kit subscriptions.
When you purchase and download your package, the transparent file names will look like this:

Note: The files labeled as “no background” will appear white or blank, as computers often display transparency in white. What you’re viewing when you click these files is a white version of your logo on top of a "white" transparent background. These files are useful if you need to put your logo on a dark or photo background.
Learn more about transparent logo files here.