ISWC
An ISWC (International Standard Musical Work Code) is a unique identifier for a musical work — the composition and lyrics, independent of any recording. It follows the format T-123456789-C: the letter T, nine digits, and a check digit. Collecting societies in the CISAC network assign ISWCs when songwriters or publishers register a work, and use them to match publishing royalties worldwide.
Format: how an ISWC is built
An ISWC follows the pattern T-123456789-C: the letter T, a nine-digit work number, and a single check digit. The T prefix marks it as a musical work code and distinguishes it from recording identifiers at a glance. The code identifies the work itself: melody and lyrics as created by the songwriters, independent of any specific recording, release, or performer. One work keeps one ISWC for life, no matter how many versions exist: the original recording, every cover, and every live version of the same composition all point back to the same ISWC. That is what lets collecting societies pool usage from thousands of sources and pay the writers of the work.
How to get an ISWC
ISWCs are assigned by collecting societies, not bought. When a songwriter or publisher registers a work with a society in the CISAC network (GEMA in Germany, ASCAP or BMI in the US, PRS in the UK), the society allocates the ISWC and shares it through the global ISWC database. To register, the writers need society membership and an IPI number, and the registration lists each participant's share of the work. With BBN Label Suite, publishing is opt-in: labels whose writers are society members can manage works and shares in the platform and export registrations as CWR files for GEMA and other CISAC societies.
ISWC vs. ISRC
An ISWC identifies the musical work; an ISRC identifies one specific recording of it. The split matters because the two sides earn separately. The recording side, master royalties from streams and downloads, flows through your distributor and is matched by ISRC. The work side, performance and mechanical royalties for songwriters and publishers, flows through collecting societies and is matched by ISWC. A song with one ISWC can have dozens of ISRCs: the album version, the radio edit, remixes, covers by other artists. If you write and record your own music, you sit on both sides and benefit from keeping both identifiers registered and consistent.
Frequently asked questions
Can I buy an ISWC?
No. ISWCs are assigned by collecting societies when a work is registered. Join a society such as GEMA, register the work with its writers and shares, and the ISWC is allocated as part of the registration.
Does a cover version get a new ISWC?
No. A cover is a new recording of the same work, so it gets a new ISRC but keeps the original ISWC. Only a genuinely new work, for example a new arrangement registered as its own work, receives its own ISWC.
Where do I find the ISWC of my song?
You find the ISWC in your collecting society's member portal once the registration is processed, or in the public ISWC database operated within the CISAC network.