Everything You Need to Know About ISWCs

The global standard for identifying musical works.

What is it? 

An ISWC (or International Standard Musical Work Code) is 10 unique characters assigned to a composition — the international standard for identifying musical works. Much like an ISRC, ISWCs help separate your compositions from similar works by pointing out a piece’s title, songwriter(s), publisher, and song splits

Pro tip: Each musical work/composition can only ever have one ISWC attached to it, so this code should never be reused to represent other musical works / compositions.

On the other hand, one musical work/composition can be linked to several ISRCs. This is because the ISWC represents the underlying composition, and the ISRC represents the sound recording. For example, someone could record your original composition, a remix of that recording, and a karaoke version — three unique performances of the same musical work, each with their own unique ISRC.  

As a songwriter, you are entitled to a share of each and every sound recording that stems from your original work. This is why Songtrust encourages you to associate as many ISRCs with your composition as possible, but only one ISWC.

Who Needs An ISWC

If you write your own music and plan on releasing it publicly, you need an ISWC. This is because it separates your composition from similar works, links it back to you and your publisher, and lets people know who needs to be paid when that composition is used commercially.

How Are ISWCs Created?

An ISWC number is made up of the letter “T” followed by 9 digits and a “check digit” that protects the ISWC against allocation errors. It follows this format: T-123456789-Z.

Songs receive ISWCs when they are registered at a Performing Rights Organization (PRO). If your song is brand new, Songtrust helps register it with your PRO so that it can be assigned an ISWC. You can also get an ISWC by visiting the ISWC International Agency and providing them with the title of your composition; the names of all contributors, along with their individual IPI/CAE number; and a work classification code.

You can find existing ISWCs by searching for your songs in the repertory section of your PRO’s website. 


Interested in learning more? Check out our blog post explaining the differences between an ISWC and an ISRC


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