ISWC vs ISRC: What's the Difference, and Do You Need Both?

The music business maintains separate identifiers for songs and recordings, yet people confuse them all the time. During a distributor upload, an MLC song registration, or a sync metadata form, you'll probably see requests for an ISRC, an ISWC, or the pair. Understanding ISWC vs ISRC matters because the codes cannot replace each other. Putting the wrong one in a field often prevents royalties from matching.

The quick distinction is simple: an ISWC marks the underlying song, while an ISRC marks a particular recording. A song has only one ISWC, though it may have numerous ISRCs because each recorded version needs one. Most writers require both. The PRO supplies ISWCs, and the distributor supplies ISRCs.

Here is the fuller explanation.

ISRC: International Standard Recording Code

An ISRC belongs to one specific master recording. Record the song at home and that version receives one ISRC. Make a new recording three years later for your sophomore album and it needs another. A remix, acoustic take, or faster TikTok edit also receives a distinct ISRC.

An example is US-ABC-26-12345:

• US: two letters identifying the issuer's country
• ABC: a three-character registrant code for the issuer, typically the distributor or label
• 26: two digits for the reference year
• 12345: the issuer's unique five-digit serial number for that year

You can read IFPI's ISRC handbook for the complete technical standard.

You can receive an ISRC from:

• Your distributor: DistroKid, TuneCore, CD Baby, UnitedMasters, Stem, Symphonic, AWAL, ONErpm, etc. Modern distributors create the identifiers automatically as part of a release upload.
• Your label, when you work with one. Most record labels have authorization to issue ISRCs.
• The RIAA directly in the US if you prefer to assign your own. Most indie artists do not need this because their distributor includes the service at no charge.

The ISRC stays attached to its recording permanently. SoundExchange uses it when paying master-side digital performance royalties, streaming platforms track plays with it, and music-recognition systems such as Shazam and content ID use it for matches. Never replace an ISRC once a recording has one, because changing the code severs downstream royalty connections.

ISWC: International Standard Musical Work Code

An ISWC represents the composition itself. The performer, recording, and number of re-recordings do not change it. Dolly Parton's "I Will Always Love You" carries a single ISWC. Whitney Houston's cover, Dolly's 1974 original, her 1982 re-recording, and every karaoke rendition all use that code because each recording is based on one composition.

Its format resembles T-123.456.789-0:

• T: the fixed prefix used for every ISWC
• 123.456.789: a unique number containing nine digits
• -0: the check digit

ISWCs are supplied by:

• Your PRO: ASCAP, BMI, or SESAC for US writers. Register a work with your PRO, and it creates an ISWC before sending the record to CISAC's worldwide ISWC registry. PROs everywhere issue these codes, including PRS in the UK, SACEM in France, and GEMA in Germany.
• Your publisher, when it has an established relationship with a PRO.

Globally, every composition should have exactly one ISWC. Co-writers affiliated with different PROs can occasionally cause two codes to be created for one song, but CISAC later combines them. For your own catalog, rely on your PRO as the authoritative source for ISWCs.

A direct comparison

Why a song needs several ISRCs

Distinct recordings of one composition always require separate ISRCs. For example, one track could produce five identifiers:

1. Its first studio recording from the album
2. A shorter radio version with censored vocals
3. The festival performance released as a live track
4. A remix arriving six months afterward
5. An acoustic take included on the artist's deluxe edition

Those five recordings still use one ISWC since the composition has not changed. Publishing systems, including the MLC, PROs, and foreign societies, follow the ISWC. Recording systems, including Spotify, SoundExchange, and your distributor, follow each ISRC.

Here is where the connection affects payment. Suppose a listener plays the remix but your distributor registered only the original recording's ISRC. That play might be excluded from your master royalties. Or suppose the MLC holds the right ISWC but has never been told that ISRC #4 also embodies that song. The remix's publishing mechanical could remain unmatched.

When each identifier matters

Use this practical breakdown:

An ISRC is required to:

• Send releases to download shops and streaming platforms
• Collect master-side digital performance royalties through SoundExchange
• Receive correct stream reports in the distributor's dashboard
• Connect tracks to TikTok and YouTube content ID databases

An ISWC is required to:

• File with the MLC, allowing it to connect composition data to streams and pay mechanicals, as covered in our MLC vs HFA breakdown
• Submit works to international performance and mechanical societies through sub-publishing
• Identify you as the songwriter in the global CISAC registry that PROs worldwide consult
• Avoid metadata problems during sync pitches, where supervisors and sync agents expect an ISWC

Both codes matter. The ISRC supports the recording pipeline, while the ISWC supports publishing. Leave out either identifier and one half of the royalty chain stops working.

Getting both codes in practice

ISRC: anyone releasing through a distributor should already have an ISRC for each catalog track. Open the distributor dashboard and check the listing for every release. Artists who released independently without a distributor may obtain an issuer code from the RIAA, although a $20-a-year distributor provides a simpler route.

ISWC: join a US PRO such as ASCAP, BMI, or SESAC, then submit each song to its work registry. Joining as a writer and registering the songs are different steps. Once a work is submitted, the PRO creates its ISWC. Remember: copy the assigned ISWC from the PRO's portal into your own records. Plenty of writers complete the song registration but never save the identifier, leaving them unable to finish an MLC form later.

For older songs lacking ISWCs in your files, search each title in BMI Repertoire Search or ASCAP ACE Repertory, which is free. International PROs offer similar searches. Our ISWC guide gives the lookup process step by step.

Common failures

We repeatedly find three issues during catalog audits for new artists:

• The ISRC and ISWC appear in each other's fields. A writer submits an MLC registration with the recording code pasted into the song-code field. Matching fails, and the royalty remains unclaimed.
• No ISWC has been included. Although the work exists at the writer's PRO, the writer never copied its ISWC into a personal metadata file. The MLC submission is therefore missing information.
• Later ISRCs are not connected to the original ISWC. The MLC cannot infer that a remix or re-recording with a fresh ISRC uses the same composition. We make those links while registering the work.

The short version

You need two identifiers because you have two royalty pipelines.

• ISRC = one recording. The distributor provides it. Master royalties use it.
• ISWC = one composition. The PRO provides it. Publishing royalties use it.

Lacking one code breaks half of the chain. Entering them in the wrong registration fields leaves that half unmatched without an obvious warning until an audit finds it. Our roster receives that audit. You can see the rates on the pricing page and read the full arrangement under publishing administration. We keep a portion only of the revenue we recover: 15% for performance royalties and 20% for mechanicals, with no setup charge or exclusivity.