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Royalties

ISRC vs ISWC: The Two Codes Your Song Needs

By Boboy Watson·Last verified August 31, 2026·1,909 words·Royalties

I moved one of my older singles from one distributor to another and did not think about identifiers at all. The new distributor generated a fresh ISRC, the release went live, and the song's entire history — the streams, the playlist adds, the editorial context, the SoundExchange record — stayed attached to a code that no longer pointed at anything I was distributing. From the outside it looked like a brand new song by an artist with no history.

That is what these codes do. They are not paperwork. They are the only thing connecting the money to you.

What is an ISRC?

An ISRC is an International Standard Recording Code. It is a 12-character identifier defined by ISO 3901, administered internationally by IFPI and in the United States by the RIAA, and it identifies one specific sound recording.

The structure carries meaning:

CC-XXX-YY-NNNNN — a two-letter country code for the registrant, a three-character registrant code identifying who issued it, a two-digit year of reference, and a five-digit designation code for the individual recording.

Two things follow from "one specific sound recording". First, the ISRC is on the master side of the copyright. It travels with the recording, which is why your distributor, SoundExchange, Spotify and YouTube Content ID all care about it. Second, the ISRC says nothing about the song. A cover version of somebody else's composition still gets your ISRC, because you made that recording.

For almost every independent artist the ISRC is issued automatically. DistroKid, TuneCore and CD Baby all assign an ISRC to every track at upload, at no extra charge, on every plan — including DistroKid Musician at $24.99/yr, TuneCore Rising Artist at $24.99/yr and CD Baby's $9.99 single, as of August 2026. You do not have to do anything to get one, which is exactly why so few people know what theirs are.

The alternative is to register with the RIAA as your own ISRC manager, which gives you a permanent registrant code and lets you issue your own ISRCs. That is worth doing if you release a lot, work across multiple distributors, or want your codes to stay stable no matter who is distributing you this year.

What is an ISWC?

An ISWC is an International Standard Musical Work Code. It is defined by ISO 15707, administered through CISAC, and it identifies one composition — the song, independent of who recorded it or how many times.

The format is T-123456789-C: the letter T, nine digits, and a check digit.

You do not apply for an ISWC the way you apply for a domain name. It is assigned by a society when a work is registered — in the United States, by ASCAP, BMI or SESAC when you register the composition, once the writers, their IPI numbers and their shares are recorded. It then shows up in your works catalogue at that organisation, and you can carry it into your MLC work registration and into any publishing administration you use.

Because the ISWC identifies the composition, it is the code that ties every recording of that song together — the original, the cover, the remix, the live version, a version recorded by someone else entirely twenty years from now. That is what makes it valuable for matching. Titles collide constantly; ISWCs do not.

How many ISRCs and ISWCs does one song have?

Many ISRCs. One ISWC. This is the relationship that explains most of the confusion.

Read the last two rows in the "no" group carefully, because they are the ones that go wrong in practice. Redistribution is not a new recording. If you switch from CD Baby to DistroKid, or from TuneCore to DistroKid, and you are delivering the identical master, that master already has an identity. Type the existing ISRC into the new distributor's field rather than letting it generate one.

Where does each code actually get used?

This is the table to keep. Each registration wants specific codes, and giving the wrong one is a silent failure.

The single most important row is The MLC work registration, because it is the one that uses both. Your MLC work record describes the composition, and you attach the ISRCs of every recording of that composition to it. That attachment is how Spotify's reported usage — which is reported by ISRC — finds its way to your composition and pays you the mechanical. If your recordings are not linked to your work, the usage arrives and does not match.

What breaks when the codes are wrong?

Every one of these produces the same visible symptom: streams are happening, and money is not arriving. The cause is different in each case.

1. Duplicate ISRCs on the same recording. Two codes for one master splits your streaming stats, your Spotify for Artists history, and your royalty reporting into two records. Each half reports separately, neither one shows your real numbers, and playlist and algorithmic history does not merge.
2. An ISRC on the MLC work registration that does not match the ISRC the distributor issued. The mechanical usage never links to the work, the money goes to The MLC's unmatched pool, and nothing in your account flags it.
3. A recording never linked to any work registration at all. The MLC has usage with no composition to pay it to. This is the default state for every artist who has distributed music but never registered with The MLC.
4. No ISRC supplied to SoundExchange. SoundExchange matches non-interactive usage by identifier. An unregistered or unmatched recording accrues royalties with no payee attached.
5. A missing or wrong ISWC across societies. Foreign societies and publishing administrators lean on the ISWC to recognise the same composition arriving from different sources. Without it they fall back to title and writer name, which is where misspellings and alternate spellings start producing duplicate work records.
6. Two work registrations for one composition. Usually caused by two co-writers each registering the song separately, sometimes at different PROs. The result is two ISWCs for what should be one song, shares that do not reconcile, and a conflict that freezes payment until it is resolved.
7. A remix or alternate version registered as a brand new composition. It gets its own ISWC when it should share the original's, so the versions never aggregate and your reporting fragments across what looks like several different songs.

Number 6 is the expensive one. A conflict on a composition does not just delay the disputed share — it can hold the entire work while the societies sort out who claims what, and unwinding it takes months of correspondence rather than a form submission.

How do I audit my own codes?

This is a two-hour job for a catalogue of twenty songs and it is worth doing once properly.

1. Build a spreadsheet with one row per recording. Columns: title, artist name as credited, release date, distributor, ISRC, UPC of the release, and the composition it is a recording of.
2. Pull every ISRC from your distributor dashboard. DistroKid, TuneCore and CD Baby all display them per track in the release details.
3. Flag any composition that appears in more than one row — those are your multi-recording works, and they are where linking errors concentrate.
4. Look up each composition in your PRO's public works search at ASCAP or BMI. Confirm the writers, the IPI numbers, the shares totalling 100%, and record the ISWC.
5. Search The MLC's public database for each title and writer name. Confirm a work record exists, that you are on it, and that the ISRCs listed against it match column five of your spreadsheet exactly.
6. Check SoundExchange for recordings registered under your artist name and any alias, side project or band name you have released under.
7. Fix mismatches at the source. A wrong ISRC on an MLC work is edited in your MLC account. A wrong ISRC issued by a distributor is a support ticket with that distributor. A duplicate work registration at a PRO is a correspondence job with the PRO.
8. Add the audit to your release checklist so the next release never enters the catalogue without its codes recorded in one place you control.

Step 1 matters more than it looks. The reason these errors persist for years is that no single system shows you all of it. Your distributor knows the ISRC and not the ISWC. Your PRO knows the ISWC and not the distribution. The MLC knows what you told it. The spreadsheet is the only place the whole picture exists.

What about the UPC?

A UPC is a third code and it operates at a different level. The UPC identifies the release as a product — a single, EP or album — while the ISRC identifies each track inside it. A four-track EP has one UPC and four ISRCs. Stores use the UPC to group tracks into one release page and to match your artwork and metadata to the right product.

Distributors assign the UPC automatically alongside the ISRCs. You need it if you are pitching to a retailer, submitting to a service that asks for a release-level identifier, or filing a claim that concerns a whole release rather than a track.

Three codes, three levels: UPC for the release, ISRC for the recording, ISWC for the song. Every royalty system you deal with cares about at least one of them, and the ones that pay the most attention — The MLC and SoundExchange — care about the ones nobody hands you on a plate.

Written from experience running my own catalogue's registrations, not as legal or accounting guidance. Identifier standards and registration procedures change — check the IFPI, CISAC and MLC documentation directly before making changes to a live catalogue.