83% of Songwriters Have Unpaid MLC Royalties-Muso.AI's Catalog Audit Targets the Black Box

83% of Writers Have Unpaid Royalties in the MLC: What Muso.AI's Catalog Audit Reveals-and How to Fix It

If you write songs, there's a strong chance you're missing money. Muso.AI's new Catalog Audit flags issues in the MLC database, and the early numbers are blunt: 83% of songwriters have a problem tied to mismatched or unregistered works.

This isn't a minor glitch. It's systemic. And it's fixable.

The core problem, in plain terms

The MLC was created under the Music Modernization Act to collect and distribute U.S. mechanical royalties from digital services. It has paid out over $3 billion, which is meaningful-until you see what's stuck.

Muso.AI's analysis points to major gaps: more than half of the MLC's ~50 million works aren't linked to any recordings, and over 70% of the ~224 million recordings in the system are unmatched. Their estimate: royalties from ~2.7 trillion streams are sitting in a black box because ISRCs aren't tied to ISWCs.

As one executive put it: "The MLC exposes their data and issues publicly, but it's up to the rights holders to fix it."

Learn what the MLC does and why accurate metadata matters. For legal context, see the Music Modernization Act.

What Muso.AI's Catalog Audit actually does

Muso.AI compares your songwriting credits against the MLC's database and generates a report of what's wrong and where. You'll see missing songs, missing recordings, wrong splits, duplicate works, and bad links between ISRCs and ISWCs.

The tool categorizes issues into two buckets:

• Unmatched: Your track exists, royalties may be accruing, but the recording isn't linked to the composition.
• Unregistered: Your track isn't in the MLC at all-even if it has millions or billions of streams.

You can share issues with collaborators, admins, and publishers. They verify, add missing credits, and fix the data. The goal is simple: stop leaving money on the table. "Every unmatched recording or unregistered song is a royalty waiting to be claimed," said the team.

Why this hits working writers the hardest

This spans decades of catalogs, from legacy songs to current hits. The biggest pile-ups are from the last 5-10 years-thanks to DIY distribution and loose registration workflows. It's not just a long-tail problem; high-stream tracks and even songs with 1B+ streams show up in the audit with issues.

Muso.AI's scale makes this viable: data on 8.5M songwriters, 179M songs, 716M credits, over 7M verified user-submitted credits-and 144M tracks flagged with MLC-related issues.

Proof from early use

Emilio Morales, Managing Director at Rimas Publishing, shared that the audit helped them detect missing ISRCs and fix ISRC-to-ISWC mismatches across their catalog. "This level of transparency is now accessible to the entire publishing community," he said. Real-time updates also help them prevent downstream royalty problems.

Run a Catalog Audit in minutes

For New & Free Users

• Go to the Muso.AI website
• Create your account
• Navigate to the Audits page
• Claim and verify your profile
• See a sample of issues in your catalog
• Upgrade to a Pro plan (songwriters/artists) or Business plan (publishers) to unlock and download your full detailed report

For Paid Users

• Go to the Muso.AI website or app
• Navigate to the Audits page
• Claim and verify your profile (if you haven't already)
• Download your full detailed report instantly

Checklist before you start

• Have your ISWC(s) for compositions and ISRC(s) for recordings
• Confirm splits and publisher/admin info
• List all collaborators and their contact emails
• Gather release URLs from major DSPs for cross-reference
• Note any alternate titles, remixes, versions, or language variants

After the report: fix and claim

• Prioritize by money: sort issues by streams and territories
• Resolve links: connect the correct ISRC to the correct ISWC
• Register missing works with the MLC (or instruct your publisher/admin)
• Unify names: standardize writer names, IPI/CAE numbers, and roles
• Kill duplicates: merge duplicate works to stop splitting royalties
• Re-check: confirm fixes in the next audit cycle and set quarterly reminders

Common pitfalls to avoid

• Duplicate works from alternate titles or translations
• ISRC reuse across releases or territories
• Stage names and legal names not mapped to the same profiles
• PRO data (IPI/CAE) not matching publisher records
• Remixes, covers, and derivative works registered as originals
• DIY releases with incomplete or missing metadata at upload

The bottom line

Most writers are affected, and the fix starts with a clear audit. Share the report, verify credits, link recordings to compositions, and register what's missing.

As the team stated: Your catalog deserves it. Your royalties depend on it.