But understandably you’re confused as to who does what.
So here it goes...
Put simply, the MLC’s job is to collect royalties for songwriters and publishers from DSPs such as Spotify.
This emerged from the signing of the Music Modernization Act.
HFA contributed to the forming of the MLC’s database.
They used to be responsible for collecting mechanicals from DSPs, but now that role has been passed onto The MLC.
If you are a songwriter, and you don’t have a publishing deal, then the simplest solution is to use a pub admin service to make sure you’re collecting your mechanicals.
The source code for the frontend of this website is available on GitHub.