You cannot govern what you cannot see.
Most of the AI in a mortgage shop arrived inside someone else’s product, and both GSEs hold the lender, not the vendor, accountable for it. Freddie Mac’s Guide § 1302.8 has been effective since March 3, with Freddie confirming that its CORE reviews will encompass the AI/ML requirements. Fannie Mae’s LL-2026-04 takes effect August 6 and requires prompt disclosure, on request, of what AI you use and the safeguards behind it. You cannot answer either until you know what is running, and the facts sit with your vendors.
So we built the tool that gets those facts: the Phase-One AI Vendor Inventory Letter, released today. It is a copy-to-your-letterhead template that lenders can send to every vendor that could conceivably touch AI, paired with a ten-item Initial AI/ML Disclosure Schedule the vendor completes and signs, including a no-AI attestation with a commitment to notify you before any AI feature is activated. The handout also tells you what to do with what comes back: how to route the five response patterns, what goes in the file, and when to escalate, and the responses populate the same AI System Inventory that MISMO’s new FRAME framework places at the center of responsible AI governance. The operating rule is simple: a vendor response is not the end of diligence; it is the first controlled record in your AI governance file. And remember that silence at inventory predicts silence at examination.
One more date for dual-channel shops: on July 7, Fannie Mae extended the same architecture to Multifamily lenders in Multifamily Lender Letter 2026-05, including the no-less-protective vendor and subcontractor standard and on-request disclosure, and reaching origination, servicing, and asset management. If you sell to both windows, calibrate the letter by channel rather than treating one form as universal.
