Metadata is the least glamorous part of releasing music and the most common reason money goes missing. A track can get playlisted, placed in a show, and streamed hundreds of thousands of times while the royalties sit unmatched, because the identifiers and credits attached to the release do not line up with what the databases expect.
None of this requires a paid service. Every standard below is published publicly, and every database used to check your own catalog is free to search.
There are two songs inside every song
Almost every metadata problem starts with one misunderstanding: a track is two separate pieces of property. The composition is the underlying song — melody, chords, lyrics — owned by the songwriters and publishers, and identified by an ISWC. The sound recording is one fixed recording of that song, owned by whoever made or paid for it, and identified by an ISRC.
A cover is a new recording of an existing composition: new ISRC, same ISWC. Live versions, radio edits, instrumentals, remasters, and sped-up edits each get their own ISRC. Get the split wrong and performance royalties chase the wrong party.
ISRC: the fingerprint of a recording
The International Standard Recording Code is a 12-character identifier administered through IFPI's International ISRC Registration Authority. It reads as country code, registrant code, year of reference, and a five-digit designation number — for example US-S1Z-99-00001.
- Assign an ISRC once and never reuse or change it, even if the recording moves to a new label or distributor.
- Assign a new ISRC to any version that differs in audio: edits, remixes, remasters, alternate mixes, live takes.
- One recording keeps the same ISRC across formats — streaming, download, and physical share the code.
- You can get a registrant prefix from your national ISRC agency, or let a distributor issue codes. Distributor codes work, but they sit under the distributor's prefix, which matters if you plan to move catalog later.
UPC and ISWC: product and composition
The UPC (EAN outside North America) identifies the release as a product — a single, EP, or album. Change the tracklist or the packaging of a release and you generally need a new product code. Most distributors issue these automatically, which is fine for nearly every independent release.
The ISWC identifies the composition and is assigned through your performing rights organization when you register the work, not by your distributor. If you write and record your own material you have two jobs: register the recording through distribution, and register the composition with your PRO and — in the U.S. — with The MLC for streaming mechanicals.
Credits: the fields nobody fills in
Credits feed liner notes, the writer fields on streaming platforms, and neighboring-rights payments for performers. The shape of this data is defined by DDEX, the standards body whose message formats distributors and DSPs use to exchange release information. At minimum, capture per track:
- Primary artists, spelled exactly as they should display — no "feat." baked into the title when a featured-artist field exists
- Songwriters with legal names, PRO affiliations, and split percentages that total exactly 100%
- Producer, mixing engineer, mastering engineer, and recording studio
- Session performers and the instruments they played
- Language, explicit flag, genre, and correct original release date
Two conventions worth adopting on your first release: pick a canonical artist name spelling and reuse it everywhere, and keep one master metadata sheet per release that goes to every partner. Inconsistent spellings are the second most common cause of split payments, right behind missing splits.
Audit your own catalog for free
- ISRC Search — the international database of assigned recording codes
- The MLC Public Search — U.S. mechanical registrations and writer shares
- MusicBrainz — an open, community-run music encyclopedia used widely as a reference dataset
- Copyright Public Records — U.S. Copyright Office registration records
- Your PRO's repertoire search — most publish a free work lookup
Search your own name in each. If your track is live on a DSP but The MLC shows nothing, that is not a cosmetic issue — distribution registers the recording, not the composition, and the mechanicals are accruing unmatched.
The short version
Unique ISRC per recording, one UPC per release, compositions registered with your PRO and The MLC, splits signed before release, credits filled in completely. It is an afternoon of work per project and it is the difference between royalties that find you and royalties that sit in a suspense account.
