The MC Number Didn't Change. The Company Did.

I tendered a load to a carrier I'd used a dozen times. MC-1247893. DOT-3567102. Five years of operating history in SAFER, zero crashes in the last two years, OOS rate well below the national average. Looked clean. Screened clean.

Eighteen months later I found out the carrier had sold its operating authority to a new LLC eight months before that load. Different principals, different drivers, different equipment. The crash-free record I was relying on belonged to the old entity. The guys who hauled my freight had been operating under that MC number for eight months with no prior safety record — just the borrowed history of the company they bought.

That's the part nobody talks about when they explain the 18-month rule. "New authority" doesn't just mean a fresh MC number. Sometimes it means a decades-old MC number with a brand-new company behind it.

How Operating Authority Actually Transfers

An MC number is tied to a legal entity, not a piece of equipment or a group of people. When a carrier business is sold, acquired, or restructured, the operating authority can transfer to the successor entity. The FMCSA registration process for this runs through 49 CFR Part 365 — the new entity files for operating rights, the prior registrant's history ties to the number, and the MC stays in service.

The successor carrier is required under 49 CFR § 390.19 to file a new or updated MCS-150 within 90 days of the change in operations — including changes in ownership, principals, or operational status. That biennial update requirement is also how carriers are supposed to keep SAFER current with new addresses, new DBA names, and new officer information.

The practical problem: not everyone files on time. A carrier that sold its authority and had the buyers assume operations might go months before a fresh MCS-150 appears in SAFER. During that window, SAFER looks exactly the same as it always did — same crash data, same OOS rate, same name, sometimes even the same contact phone number. You'd have no way of knowing from a quick MC pull that you're looking at a new entity riding an old track record.

That's not a theoretical edge case. It happens in asset-light acquisitions all the time. Private equity buys a regional carrier, keeps the MC number, folds in different drivers and equipment, and the prior safety culture walks out the door with the prior owners.

What SAFER Actually Shows You — and What It Doesn't

The most underused field in the SAFER company snapshot is the MCS-150 date. Not the "entity created" date. Not the DOT registration date. The date the carrier last filed an MCS-150 update.

If you're looking at a carrier with 15 years of operating history and the MCS-150 was updated six months ago, ask why. Biennial updates are due every 24 months; carriers that update on schedule will show a date 18–24 months old. A recent update on a long-tenured carrier is sometimes just routine compliance. But it can also mean a change in operations, ownership, or classification triggered a new filing.

The other thing to cross-reference: the company name against what you have in your carrier agreement. SAFER shows both the registered legal name and any DBA. If the name in your carrier packet is "Lone Star Freight LLC" and SAFER shows "Lone Star Freight LLC, DBA Mountain Transport Solutions," you're looking at either a rebranding or an acquisition — and you should know which.

The officer/principal section is trickier. SAFER doesn't always list current principals, and when it does, it can lag a transfer by months. But if the name in SAFER's contact section doesn't match the signatory on the carrier agreement you're carrying in your file, that mismatch alone is worth a phone call.

Insurance filing history via the FMCSA L&I (Licensing and Insurance) page is the sharpest signal. When authority transfers, there's frequently a gap in active insurance coverage — even if brief — as the new entity stands up its own policy and gets the insurer to file BMC-91 or BMC-91X with FMCSA. A gap in coverage that aligns with a recent MCS-150 update is about as clean a confirmation of a recent ownership change as you'll find in public records. It means the prior insurer dropped off the filing and the new one picked up — that transition is visible if you look.

The Safety History Problem

Here's the thing about BASIC percentiles on a carrier that just transferred authority: the crash indicator and vehicle maintenance numbers you're reading reflect violations and crashes accumulated by the prior entity. They might have nothing to do with the compliance posture of the people now running the trucks.

This cuts both ways. A carrier with a clean crash history that transferred authority to a new entity with poor safety practices will look better than it is for months after the transfer — until their violations and crashes accumulate. Conversely, a well-run new entity that acquired an MC number from a poorly-run prior carrier will look worse than it is until the old history ages off. Either way, you're making a judgment call based on a safety record that isn't entirely current.

The 18-month heuristic breaks here. The whole point of that rule is to limit exposure to entities with no operating track record. A carrier with five years of operating history should theoretically have five years of safety data to evaluate. But if the underlying entity changed hands a year ago, you've got one year of relevant safety performance and four years of noise from someone else's operation. The number of years of authority doesn't tell you the number of years the current management team has been running.

What you actually want to know: how long have the current officers been operating under this MC number? That's not a question SAFER can answer directly. It's a question a phone call can answer. And after Montgomery v. Caribe Transport II, the question "did you verify who you were actually dealing with" is one that will get asked in discovery if the load goes wrong.

What Continuous Monitoring Is Actually For

Most brokers think of carrier monitoring as a way to catch insurance lapses. That's real — a policy that cancels mid-week and reinstates by Friday is the kind of thing only monitoring catches. But the more underappreciated use case is exactly this: catching authority changes before you tender.

When a carrier updates their MCS-150 with new principals, a new address, or a new DBA, that's a material change in the entity you screened. If you vetted MC-1247893 in January based on a screen that captured the old management team, and in March they sold to a new LLC that filed a new MCS-150, your January screen is no longer an accurate picture of who you're dealing with. It's an accurate picture of who you were dealing with.

DOTScreener's Continuous Monitoring re-runs the carrier screen when FMCSA data changes and logs a new Carrier Selection Record with a fresh timestamp. That re-filed record is the document that shows your diligence wasn't a one-time event — it was an ongoing process that caught a material change and required a fresh look. That's a very different paper trail than "I screened them 14 months ago and have been booking them on autopilot ever since."

The re-screening trigger isn't in the FMCSR by name. 49 CFR Part 385 governs safety fitness determinations and doesn't tell you how often to vet your carriers. What it tells you, by implication, is that safety fitness is a current determination — not a permanent one. The plaintiff's attorney in a post-Montgomery negligent-selection case isn't going to ask when you first screened the carrier. They're going to ask when you last screened the carrier, what you did with what you found, and whether anything material had changed that you should have caught. A fresh screen triggered by a monitoring alert answers all three.

How I Document This

When I screen a carrier, I capture the SAFER snapshot including the MCS-150 date. If the MCS-150 date is recent relative to the carrier's years in operation — anything less than 18 months on a carrier with 5+ years of history — I note it in the carrier file and verify with a phone call.

Specifically, I look for:

• MCS-150 filing date vs. the "entity created" date: a recent filing on an old carrier needs an explanation.
• Insurance filing history on L&I: a gap in coverage in the last 12 months that aligns with a recent MCS-150 update is a transfer signal.
• Officer/principal name in SAFER vs. the signatory on the carrier agreement: a mismatch means you're dealing with someone you didn't formally vet.

If I find any of these, I document the discrepancy, note the resolution (phone call, updated carrier packet, re-signed carrier agreement with current principals), and re-run the full screen. That chain of documentation — original screen, noted discrepancy, investigation, updated screen — is what holds up when someone reads the carrier file later.

The broader point is that a carrier isn't a static entity. It's a legal construct that can change hands, change officers, change equipment, and change safety culture while the MC number stays exactly the same on your screen. The screen is a snapshot. The monitoring is the thing that tells you when the snapshot is out of date.

One-time vetting treats a carrier file as a box to check. Continuous vetting treats it as a living record. After Montgomery, the difference between those two postures is the difference between a defensible file and a gap in discovery.

— Mason Lavallet

Founder, DOTScreener.com