DISCLAIMER
Even though royalties should work roughly the same everywhere, everything which follows is written from an EU point of view. Always make sure about the conditions of each company you are signing with.

This thread will be constantly updated with new info acquired.
Please, feel free to correct the OP or add missing information in this and any other thread in this community.

In this thread, I’d like to gather the most important information that every musician should know about royalties.
TL;DR sign up with a PRO and with SoundExchange (or analogue) and claim all your songs.

Performance Rights Organisation (PRO)

What does a PRO do

A PRO (typically) collects the following royalties:

1) Performance Royalties;
  • Performance royalties are generated when a musical work is publicly performed. Public performances include plays on radio, television, live concerts, clubs, restaurants, streaming services, and other public venues.
2) Mechanical Royalties; (this could be collected by labels and distributors)
  • Mechanical royalties are generated from the reproduction or distribution of recorded music. This includes sales of physical copies (CDs, vinyl) and digital downloads or streams.
3) Synchronization Royalties;
  • Sync royalties are earned when a musical work is synchronized with visual media, such as movies, TV shows, commercials, video games, or online videos.

Who should sign up

  1. Songwriters;
  2. Publishers;

Which PRO to choose

There are many PROs in the world and theoretically, they should provide the same service (plus/minus).
Normally, you might prefer the PRO which is located in your country, for easier communication and easier taxation process.
However, each PRO has its practices, systems, processes and so on (eg. annual fee), so you can check and choose which one overall suits you the best.
You can possibly register in more than one PRO, but you cannot delegate 2 PROs to collect royalties for the same country.
Ultimately, it shouldn’t matter for which PRO you sign for, all of them should collect the same royalties and worldwide.
I will start a list of PRO (by country, alphabetically) with which I had some (direct or indirect) experience. I will add more if somebody provides information.

Digital Performance Royalties (DPR)

What does a DPR collecting company do

A company working on DRP (typically) collects the following royalties:

1) Digital Performance Royalties;

Digital performance royalties are generated when a recording is performed on non-interactive digital platforms such as internet radio, satellite radio, and streaming services. These royalties are only related to the actual sound recording.

Who should sign up

  1. Recording artists (including session and featured musicians)
  2. Copyright owners (eg. labels, producers, could be the artist itself)
  3. Managers of the above mentioned

Which DPR to choose

Like PROs, there are many companies which do this, and the same rules apply here.
As above, here’s a list by country ordered alphabetically: