TL;DR
An ISRC mismatch means two different identifiers are tracking the same recording — or your correct ISRC isn't connected to your PRO registration. Either way, streaming royalties can't be matched to you and go uncollected. The fix requires correcting the metadata at your distributor and re-registering with your PRO using the correct ISRC.
When Marcus released his debut album through DistroKid in 2022, he did everything right: registered with ASCAP, uploaded to every major streaming platform, got playlist placements. By 2024 he had 4.2 million streams on Spotify alone. His ASCAP statement showed $214.
The problem wasn't ASCAP. It was his ISRC.
His distributor had assigned ISRCs at upload. His PRO registration had different ISRCs — the ones from an earlier self-release on a different platform. Spotify reported plays under the DistroKid ISRCs. ASCAP looked for those ISRCs in their system and found nothing. The connection between 4.2 million plays and Marcus's PRO account simply didn't exist.
This is an ISRC mismatch. It is not an edge case. According to industry estimates, metadata discrepancies of this kind affect a significant portion of independently released music, with The MLC alone holding over $400M in unmatched mechanical royalties, according to The MLC's 2023 Annual Royalty Recap.
What Is an ISRC and Why Does It Matter?
An ISRC (International Standard Recording Code) is a 12-character identifier assigned to a specific sound recording. It looks like this: US-RC1-26-00001. Every recording should have one — and only one.
When your song plays on Spotify in Germany, here's the chain that should result in a royalty payment:
- Spotify reports the play using the ISRC attached to your recording
- The report goes to GEMA (Germany's CMO), which cross-references the ISRC with your publishing registration
- GEMA matches the play to your PRO (e.g., ASCAP or BMI)
- Your PRO credits your account
If the ISRC in Spotify's system doesn't match the ISRC in your PRO registration, the chain breaks at step 2. The play is logged. The money is collected. But it can't be attributed to you.
How ISRC Mismatches Happen
There are four common causes:
1. Multiple distributors assigned different ISRCs to the same recording. If you uploaded a song to DistroKid, then later re-uploaded to TuneCore or CD Baby, each platform may have assigned a new ISRC. DSPs now have two different ISRCs for the same recording in their systems. Your PRO registration references only one of them — so plays reported under the other one are unmatched.
2. You registered with your PRO before finalizing distribution. Some artists register songs with ASCAP or BMI using self-generated or temporary ISRCs, then distribute with a different ISRC assigned by their distributor. The PRO record and the distributor record never connect.
3. Re-releases and remastered versions. Technically, a remaster should get a new ISRC. In practice, many artists reuse the original. This creates ambiguity in royalty systems that rely on exact ISRC matching.
4. Aggregator errors. Some distribution platforms have historically had bugs that assigned ISRCs incorrectly or failed to pass them through to DSPs. DistroKid, TuneCore, and others have all had documented periods of ISRC passthrough issues.
How Much Is an ISRC Mismatch Costing You?
The dollar impact depends on your stream volume and territory distribution. A useful benchmark: ASCAP distributed over $1.759 billion in royalties in 2025 — a record — according to ASCAP's annual report. BMI's last published annual revenue (FY2022, before going for-profit) was $1.573 billion, per BMI's final annual report. Together these two PROs distribute billions in US performance royalties annually — and a meaningful fraction of it goes uncollected because of metadata issues.
For a working independent artist with 500,000 monthly streams, a complete ISRC disconnect can mean $800–$2,000 per year in uncollected performance royalties in the US alone. Internationally, the loss is often larger: CMOs in Germany, the UK, Japan, and Australia also rely on ISRC matching, and independent artists are particularly underrepresented in international royalty flows.
How to Check If You Have an ISRC Mismatch
Step 1: Find the ISRCs on your actual releases. Log into your distributor dashboard (DistroKid, TuneCore, CD Baby, etc.) and find the ISRC for each track. Download a full catalog export if available. Write them down.
Step 2: Find the ISRCs in your PRO registration. Log into your ASCAP or BMI account. Under your registered works, find each song and check what ISRC is recorded. Compare it to step 1.
Step 3: Check your MLC registration. Go to themlc.com and search for your songs. The MLC database is public. Look at the ISRCs associated with your works. If they're different from your distributor ISRCs, you have a mechanical royalty mismatch in addition to the performance royalty mismatch.
Step 4: Spot-check on a DSP. Use Spotify for Artists or Apple Music for Artists to see which ISRC is attached to your track in those platforms' systems. This is the ISRC being reported in royalty statements. It needs to match what's in your PRO and MLC records.
How to Fix an ISRC Mismatch
Option A: Update your PRO registration to match your distributor ISRC. This is the most common fix. Log into ASCAP or BMI and edit your work registration to add or correct the ISRC. Both platforms allow ISRC additions on existing registrations. For BMI, use the work registration portal. For ASCAP, use ACE (the work registration system).
Option B: Update your distributor to use your canonical ISRC. If you have an established ISRC from a previous release, you can sometimes instruct your distributor to use it. DistroKid allows ISRC input during upload. This is harder to do retroactively but prevents future mismatches.
Option C: Register the correct ISRC with The MLC. Go to themlc.com and claim or update your work registration to include the correct ISRC. The MLC's unmatched royalties database relies on ISRC data — adding the right one can unlock retroactive mechanical payments.
Option D: File a CWR correction. For catalogs with many mismatches, a CWR (Common Works Registration) file is the industrial-strength solution. CWR is the standard format PROs use for bulk registrations and corrections. Most independent artists don't file CWR directly — it requires technical knowledge of the format and direct relationships with PROs. This is one of the core things CreateBase handles.
The International Dimension
ISRC mismatches are worse internationally than in the US, because:
- International CMOs (GEMA, PRS, JASRAC, SOCAN, APRA AMCOS, and 150+ others) each have their own databases
- They rely heavily on ISRC matching to identify works
- There is no centralized "fix it here" portal for all of them
When you correct your ISRC with ASCAP, ASCAP can forward the updated information to affiliated societies through reciprocal agreements. But the update doesn't always propagate correctly, and some CMOs have processing delays of 6–18 months.
This is why international royalty gaps tend to accumulate: a mismatch that began in 2022 may still be generating unmatched royalties in Germany in 2026, four years later. The money doesn't disappear — it sits in a black box until it's claimed or redistributed.
What CreateBase Does About ISRC Mismatches
CreateBase audits your entire catalog for ISRC mismatches as part of every engagement. Specifically:
- We cross-reference your distributor ISRCs against your PRO registrations (ASCAP, BMI, MLC, SoundExchange)
- We identify every recording with a disconnected or missing ISRC
- We file the corrections at each PRO and the MLC
- For international mismatches, we file CWR-formatted corrections that propagate through your PRO's network of affiliated CMOs
- We verify that the corrections land correctly — not just that the filing went out
Find out what ISRC mismatches are costing your catalog → CreateBase delivers a free personalized royalty gap report within 48 hours.
Frequently Asked Questions
Q: What happens to royalties collected under a mismatched ISRC?
A: They go into a "black box" — a holding pool of collected-but-unmatched royalties at the PRO or CMO. In the US, The MLC holds unmatched mechanical royalties for a minimum of three years before redistributing them to publishers based on market share, per the Music Modernization Act (17 U.S.C. § 115). Performance royalties at ASCAP and BMI have similar holding periods. After that window, the money is redistributed — primarily to major publishers, not to the original rights holder.
Q: Can I have multiple ISRCs for the same recording?
A: Technically, each distinct recording should have exactly one ISRC. In practice, many recordings end up with multiple ISRCs because of re-uploads or distributor errors. Having two ISRCs for the same recording means royalties get split between two identifiers — neither of which may be the one in your PRO registration.
Q: How long does it take to fix an ISRC mismatch?
A: Correcting the registration at a US PRO (ASCAP, BMI, MLC) typically takes 4–8 weeks to process and propagate to their systems. International CMOs can take 3–12 months, depending on the society. Royalties generated after the correction is processed will flow correctly. Retroactive recovery of royalties from before the correction depends on whether the black box funds are still in the holding period.
Q: Do distributors automatically register my ISRC with PROs?
A: No. Distributors (DistroKid, TuneCore, CD Baby, etc.) handle master recording distribution to streaming platforms. They do not register your works with performing rights organizations. That registration — and the ISRC alignment between your distributor record and your PRO record — is your responsibility.
Q: What is a CWR file and do I need one?
A: CWR (Common Works Registration) is an industry-standard XML format used to register and update works in bulk with PROs. It's the most reliable method for correcting ISRC mismatches across multiple works and multiple PROs simultaneously. Individual artists rarely file CWR directly — it requires technical knowledge of the format and direct submission access to PRO systems. For catalogs with more than 10–20 mismatches, CWR corrections are significantly more efficient than manual portal edits.
Sources
- The MLC 2023 Annual Royalty Recap — Over $400M in unmatched mechanical royalties; $3B+ distributed since 2021
- ASCAP Annual Report 2025 — $1.759B distributed in 2025 (record)
- BMI Annual Report FY2022 — $1.573B distributed (last published before going for-profit)
- Music Modernization Act, 17 U.S.C. § 115 — Three-year holding period for unclaimed MLC royalties
- ISRC International Agency — ISRC assignment and standards