what is a ISWC

The ISWC: The Secret Identification of Songs

When someone asks us to unequivocally identify a song in the digital world, they most likely expect to receive a link to that song on YouTube, Spotify, SoundCloud, or any other streaming platform. Honestly, a few years ago, I would have expected exactly the same, and I would have been puzzled if someone had said to me, “Hey! Have you heard the song ‘T-919.706.744-0’? It’s beautiful! What are you waiting for to listen to it?”

Indeed, this little number, starting with a ‘T’ followed by 10 digits, is called the ISWC (International Standard Musical Work Code), and although we might not have any idea what it is at first, it turns out to be a key component in the functioning of the music industry. In fact, it’s much more important than a link to that song on any YouTube video… surprising, isn’t it?

But… What exactly is the ISWC? Where does it come from? Why is it so important? How can you find out the song we mentioned at the beginning of this article? Let’s find out!

What is the ISWC?

As we’ve mentioned, the ISWC or International Standard Musical Work Code, is a unique and special code assigned to each musical work, serving to identify it unequivocally all over the world.

This code not only belongs to the song itself but also connects it with its composers, lyricists, artists, and bands who perform this song, and even to its different versions, which creates a package of musical identity.

The ISWC is composed of the letter “T” (for “Title”) followed by 9 digits plus a “check digit” that helps to protect the ISWC against assignment errors. Currently, the range of numbers used can assign ISWCs to one billion works, although this can be expanded when necessary.

A very important detail to keep in mind is that the ISWC is not an identification code for a version of a song, but rather it identifies its underlying composition, which is something that typically remains stable between versions, mixes, and remixes. The code that identifies the recordings, which we will discuss in future posts, is called ISRC and operates at a different level from the ISWC. Therefore, a song should only have one ISWC, but it can have several ISRCs if multiple versions of the same song have been made.

Where does the ISWC come from?

The history of the ISWC begins in the 1990s, three years after the release of the mp3, which marked the beginning of the digital revolution in the music industry. It was then that the music world realized the need for a standardized system to identify musical works, and the International Confederation of Societies of Authors and Composers (CISAC) proposed creating a unique code for each song: the ISWC. 

The first song to receive an ISWC was “Dancing Queen” by ABBA, followed by many more. The ISWC, in its early years, proved its usefulness, and in 2002, it was adopted by ISO, the leading organization in the development and implementation of standards. Since then, especially with the onset of the 100% digital era, the ISWC has become an indispensable code for ensuring the correct identification of musical compositions and their authors.

Why is the ISWC important?

1. It is a clear and unique identifier: The ISWC ensures that each song has its own unique identity. In situations where millions of songs are involved, many of which may share the same title and have authors with very similar names, the ISWC allows them to be quickly differentiated and identified.

2. It is used as a reference for the distribution of royalties: When a song is played on the radio, in a concert, or in a social media video, the people who composed it deserve to be rewarded. The ISWC helps track all those plays and links them to the song’s composers, ensuring they are appropriately compensated.

3. It facilitates the lives of artists and other music industry professionals: All its advantages derive from the same fact: its status as a unique code. Without it, properly identifying compositions, in a world where there are millions and millions of songs and artists, would be an extremely complicated task.

How to Obtain the ISWC for Your Song:

ISWCs must be obtained through copyright societies or management entities. To do this, you, or another member of your music group, must be affiliated with a copyright management entity, and register the song there, completing the metadata of the work in the best possible manner. The entity will then proceed to validate this data (especially the title, and composers’ name and identification details). After approval, the entity will request a new ISWC for the song. Make sure to add the new ISWC to your personal database and to the metadata of your audio file, as it will be very useful to present along with the song no matter what future use you intend for it.

How to Find the ISWC of a Song:

ISWCs that have already been assigned to a specific composition can be searched in various types of musical databases, copyright societies’ websites, or even, sometimes, in the credits of an album or single. A very intuitive portal for identifying ISWCs is the ISWC System, which allows you to easily search for a song’s information given a known ISWC… or identify that ISWC if you know certain details like the song’s title and one of its authors.


So there you have it, the mystery of the ISWC solved. It is the key that opens the doors to music, ensuring that every note and lyric are recognized and respected. The next time you listen to your favorite song, remember that behind those chords there is a small code that makes it possible for that listening, and what it implies, to be taken into account.

Have you tried searching for the song we talked about earlier? Isn’t it easy now that you’ve read this article? We truly hope it has helped you!


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