Work registration is the process of formally registering a musical composition with PROs, The MLC, and foreign CMOs so that royalties earned by the work can be matched and paid to its writers and publishers. Without registration, royalties accrue but get held as "unmatched" — money sitting in CMO clearing accounts waiting for someone to claim it.

A complete work registration includes: title, ISWC, every writer's name + IPI + share %, every publisher's name + IPI + share %, original release date, and territory (usually WORLD).

In practice, work registration happens through three channels:

• Your PRO portal — register works directly via your PRO's web interface (BMI, ASCAP, SESAC each have one).
• The MLC portal — register works with The MLC for US mechanical royalty matching.
• CWR file transmission — for international and bulk registration, CWR files are sent via SFTP to MusicMark (US joint PRO hub) or directly to foreign CMOs.

Producer Tour's writer program handles work registration across all three channels as part of its 20% commission.