# Substradium

> Substradium Inc. is a records custodian in Austin, Texas. It keeps dated copies of public federal and state motor-carrier records and states, for one carrier and one date, what those records showed.

## Pages

- [Why public carrier lookups cannot tell you a carrier's status on a past date](https://substradium.com/learn/past-carrier-status/): what a public lookup shows, why later changes replace what it showed, a worked example, and what a dated copy made at the time adds. By Stephen D. Daniel, Founder, Substradium Inc. Published 2026-09-25, updated 2026-10-21.
- [What changed in FMCSA's public carrier records in May 2026](https://substradium.com/learn/fmcsa-record-change/): what FMCSA's May 14, 2026 notice retired, what the Federal Register notice on Motus says, what the public history files held when read on 2026-10-30, and why a copy made on the date differs from a file read later. By Stephen D. Daniel, Founder, Substradium Inc. Published 2026-10-30.
- [Check a carrier and a date](https://substradium.com/check/): free, no account. Enter the carrier's USDOT number and a date. The page that opens shows which records Substradium was capturing on that date and how many archived rows it holds dated since. It shows registry identity and archive coverage only and makes no statement about the carrier's status, safety, or insurance. A USDOT this archive does not hold is answered as no archive, never as clean.
- [AsOf Report](https://substradium.com/asof/): the Point-in-Time Carrier Record Report. For one carrier and one date, what Substradium's dated copies of the public record show, with the source and capture time of every fact. A report contains the operating-authority timeline, the insurance filings on record as of the date, inspection and crash history available to the public record at the time, and a provenance appendix naming each fact's dataset, capture date and archive fingerprint. Each finding is labeled Captured, Reconstructed or Not captured. A certified record with the records custodian's declaration, $1,500 for one carrier and one date, delivered as a PDF, an HTML copy and a JSON copy.

## Does FMCSA SAFER show a carrier's status on a past date?

No. The SAFER Company Snapshot and the other public carrier lookups show the record as it stands now. A later action replaces what they showed before.

## Can I rebuild a past date from the federal history files?

Only in part. The history files list past events with their dates, but they are the record as it stands today, including actions entered or dated back after your date. They show what is on file now about that date, not what the record showed on it.

## What does a dated copy made at the time add?

It shows what the record said on or before the date, with the source and capture time of each fact, and a fingerprint that shows the copy has not changed since. A copy that was not made at the time cannot be made later.

## How do I ask about a carrier and a date?

Use the request box on https://substradium.com/learn/past-carrier-status/ or write to hello@substradium.com with the carrier's MC or USDOT number and the date. We reply by email within one business day with what the archive holds for that date. Nothing is charged for a request.

## MCP server

com.substradium/carrier-records, at https://substradium.com/mcp. Tools: carrier_record, carrier_record_by_docket, verify, specimen, coverage. The free tools qualify a carrier and a date and return no row of the record; every qualification answer carries order_url and the posted price. The record itself is bought, $1,500 for one carrier and one date, by request at https://substradium.com/asof/#order or hello@substradium.com. The specimen tool and https://substradium.com/asof/specimen/ return one sample record with the carrier withheld; its receipt hashes are sample labels that do not verify at https://substradium.com/verify/.

## Contact

Substradium Inc., 108 Wild Basin Rd South, Ste 250, Austin, TX 78746. hello@substradium.com.