What Are ISRC and ISWC Codes — and Why Missing Metadata Costs You Royalties

A song can generate millions of streams and still miss royalties — simply because its metadata is incomplete. ISRC and ISWC are the codes that help royalties find the right owner.

Disclaimer: This Article is for general informational purposes only and does not replace legal advice for specific situations.

TL;DR

International Standard Recording Code (ISRC) and International Standard Musical Work Code (ISWC) are not two versions of the same identifier. ISRC identifies a specific sound recording; ISWC identifies the underlying musical work. They exist because a song is two separate legal objects owned by potentially different parties, and the codes are the mechanism by which royalty systems connect the two. 

When one code is missing, wrong, or unlinked, the usage is still counted and the money is still collected — but it cannot be matched to an owner, and it accumulates in what the industry calls the "black box".

Two Codes, Two Rights Layers

The reason there are two codes rather than one is that copyright treats a song as two distinct objects: 

• The Composition — melody and lyrics as written — is protected as an authorial work belonging to Songwriters and their Publishers. 
• The Sound Recording is a separate object belonging to whoever produced or financed it. 

Each layer gets its own identifier, and the two are not interchangeable.

The practical consequence of this table sits in the last two rows. CISAC states plainly that the ISWC identifies a musical work by reference to its title and creators, and that it does not serve to identify instances of use of that work in manifestations such as recordings or broadcasts [3]. 

Example: A cover version, a remix, a radio edit, and a remaster of the same song are four different recordings carrying four different ISRCs — but they may all embody a single composition carrying one ISWC. 

Conversely, ten thousand streams of a recording generate obligations on both layers simultaneously, and the systems paying out on each layer will not find each other unless both codes are present and correctly associated.

See more: "Who Owns Music Copyright?"

Metadata with ISRC and ISWC

The codes alone are not enough — they need to be correctly embedded and linked through metadata.

When assigning an ISRC to a sound recording, the recording metadata should accurately identify the recording, including the title, artist, recording owner, and other relevant rights information. The underlying musical work should likewise be registered with the corresponding songwriter, publisher, ownership shares, and ISWC where available.

Keeping these identifiers and ownership details consistent across distributor, platform, and collective management databases allows royalty systems to connect a specific recording to the musical work it embodies. In practice, assigning the codes is only the first step; linking them through accurate, consistent metadata is what makes the codes useful for royalty matching.

How Each Code Is Allocated

The two codes are issued through different institutions and, importantly, at different moments in a release timeline.

ISRC is allocated by the recording's registrant — typically the producer or label — using a registrant code obtained from a national ISRC Registration Agency. IFPI, appointed by ISO as the International ISRC Registration Authority in 1989, has appointed dozens of national agencies worldwide [1]. 

Two allocation rules matter more than the rest in practice. 

• First, any new or materially changed recording is expected to receive a new ISRC, and re-use of a code already allocated to a different recording is not permitted [1]. 
• Second, if a recording is sold or licensed and then re-released unchanged, the ISRC stays the same [1] — meaning catalogue transfers do not create new codes, and a change of owner does not reset the identifier.

ISWC works differently. It is allocated by a Registration Agency only once all creators of the work have been uniquely identified [4]. In the ordinary path for a songwriter, this happens as a consequence of registering the work with a collective management organisation or performing rights organisation, which transmits the registration onward to CISAC [6]. 

Because identification of every creator is a precondition, an incomplete split sheet or an unregistered co-writer can hold up allocation entirely. ASCAP notes that all writers must be identified with an IPI number before an ISWC can be assigned, and that a co-written song carries several IPI numbers but only one ISWC [6].

Two caveats are worth carrying forward. Duplicate ISWCs do occur: 

• CISAC's own portal acknowledges that in a limited number of cases more than one code has been issued for the same work, and it designates a "Preferred ISWC" to resolve the ambiguity [5]. 
• The absence from the ISWC registry carries no legal meaning — the portal explicitly warns that a work not appearing there is not thereby in the public domain or free of rights [5].

Where the Chain Breaks

Metadata failures do not usually announce themselves. Nothing is rejected; no error message reaches the artist. The usage is logged, the royalty is calculated, and the payment simply stops one step short of a named recipient. The sequence below traces where that typically happens.

See more: "Which Royalties Are You Missing Out On Without Knowing It?"

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What Unmatched Money Actually Looks Like

The black box is not a metaphor for lost revenue in the abstract. The Mechanical Licensing Collective defines it as a pool of royalties that rights holders could not see, search, or quantify because the paying party did not share the underlying data, and puts the U.S. digital audio mechanical black box that existed before its own launch at approximately $426.9 million in unpaid historical unmatched royalties accrued by 21 digital services between 2007 and 2020 [10].

Two features of that pool are worth noting. 

• It was not money anyone refused to pay — it was money that had been collected and could not be assigned. 
• And it does not necessarily return to the correct owner by default: reporting on the transfer noted that after a defined matching period, remaining unmatched amounts may be distributed to publishers on a market-share basis , a mechanism that pays out the pool without the original earner necessarily receiving their share. 

CISAC framed the same problem from the composition side when it observed that reliable work data is crucial to proper collection and distribution, in a market where societies process very large volumes of digital usage [7].

See more: "What is Mechanical License?"

The Vietnam Position

Vietnam has adopted ISO 3901 into its national standards system as TCVN 11271:2015, which sets out the 12-character, four-element ISRC structure and provides that the country element reflects where the registrant's head office is located at the time the code is assigned [2]. That standard also addresses transfer: where the original producer sells a recording with all rights before an ISRC has been assigned, the purchaser becomes the registrant for ISRC purposes [2].

What Vietnamese law does not appear to do is impose a statutory obligation to attach ISRC or ISWC to delivered metadata. The Law on Intellectual Property establishes who owns what — the producer's exclusive reproduction and distribution rights under Article 30, ownership vesting in the investing party under Article 44, and a fifty-year protection term for producers' rights under Article 34 [11] — but identifier discipline in Vietnam operates primarily as a contractual and operational matter rather than a statutory duty. The practical implication is that a Vietnamese rights holder's identifier hygiene is enforced by the collection chain rather than by the regulator: incomplete metadata does not create legal liability, it creates unpaid royalties.

The cross-border dimension sharpens this. Because most territories outside the United States license through local collective management organisations that build repertoire databases from data submitted by rights owners, foreign societies commonly require more metadata than a domestic body does — including fields that exist specifically to demonstrate a recording's eligibility for foreign royalties [9]. A Vietnamese recording that travels well internationally but travels thinly documented may be earning in territories where nobody can identify it.

See more: "CMO in Vietnam & How It Fits the Vietnam Ecosystem?

Practical Takeaway

Missing metadata is usually not a rights problem — it is a matching problem. A release may go live before the composition is registered, a co-writer may remain unidentified, or a remaster may carry the wrong ISRC. The rights still exist, but incomplete metadata can prevent royalty systems from connecting usage to the correct rightsholder. In a data-driven royalty system, accurate ISRC, ISWC, and ownership metadata are not administrative details — they are what make the rights discoverable and payable.

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References

[1] International Standard Recording Code (ISRC) Handbook, 4th Edition (2021), International ISRC Registration Authority, IFPI;

[2] TCVN 11271:2015 (ISO 3901:2001), National Standard on Information and Documentation — International Standard Recording Code (ISRC);

[3] CISAC, International Identifiers — ISWC and ISNI (official guidance);

[4] ISWC.org, Allocation of ISWC — Registration Agency Guidance, CISAC;

[5] ISWC-Net Portal Terms and Introduction to ISWC, CISAC;

[6] ASCAP, ISWC and Work Codes — Member Guidance;

[7] CISAC, ISWC System Upgrade Announcement (2019), referencing ISO 15707:2001 adopted 2002;

[8] SoundExchange, All About ISRCs (2023);

[9] SoundExchange, Maximize Your International Royalties with Augmented Metadata;

[10] The Mechanical Licensing Collective, Illuminating the Black Box for Digital Audio Mechanicals;

[11] Articles 30, 34 and 44, Law on Intellectual Property No. 50/2005/QH11 (2005, amended 2009, 2019, 2022).