Several identifier codes run through the global royalty system. Each does a different job, and missing or incorrect codes at any point in the chain can stop your royalties from flowing.
IPI (interested party information) number
Your IPI is your personal identifier as a songwriter or composer across the global system. It is an 11-digit number issued by your CMO when you become a member – in the UK, you receive it when you join PRS. If you write under more than one name, you can have a separate IPI for each pseudonym; both link back to you. Older systems and documents may refer to this as a CAE number (from the French: Compositeur, Auteur, Editeur). The number is the same regardless of which term is used.
ISWC (international standard musical work code)
An ISWC identifies a specific composition. Unlike your IPI, which identifies you as a person, an ISWC identifies a specific song or instrumental work. It is assigned after your work is registered with a CMO and stays with that work permanently, regardless of who publishes or records it. A single song has one ISWC no matter how many recordings of it exist.
ISRC (international standard recording code)
An ISRC identifies a specific recording of a work. The same song might have dozens of ISRCs – one for each recording, remix, or version – but only one ISWC. ISRCs are assigned by labels or distributors, not by CMOs. The format includes a country code, a registrant code, a year, and a designation code (e.g. GB-ABC-20-00001).
The link between them
Every recording (identified by an ISRC) needs to be matched to the underlying composition (identified by an ISWC). That match is what ensures mechanical royalties flow correctly from streaming services through to songwriters. If a recording has no linked ISWC, or is linked to the wrong one, the publishing royalties have nowhere to go.
ISNI (international standard name identifier)
ISNI is a newer ISO standard identifier that works across all creative industries, not just music. It is a 16-digit number. While not yet universally required, it is increasingly used in digital systems and may become more relevant as AI attribution and global rights tracking develop.
IPN (international performer number)
If you are also a performing artist, your IPN identifies you specifically as a performer on recordings – distinct from your role as a songwriter. It is used by PPL and equivalent organisations for neighbouring rights payments. It is separate from your IPI.
