MC Numbers Going Away? 7 Motus and USDOT Changes

Last reviewed: October 2026. This article reflects FMCSA’s current published guidance and should be updated if FMCSA issues a final rule changing MC Number use.

What is an MC Number?

An MC Number is a docket number historically associated with certain types of interstate operating authority administered by FMCSA. Brokers, for-hire motor carriers, and freight forwarders have long used MC Numbers as a familiar shorthand when discussing federal operating authority.

FMCSA now says MC Numbers were never the statutory or regulatory identifier for the business itself. The USDOT Number has become the universal identifier for FMCSA-regulated entities, while operating-authority records describe what type of service the entity is permitted to provide.

Did Motus eliminate MC Numbers in May 2026?

No. Motus launched to all users in May 2026, but FMCSA explicitly states that eliminating MC Numbers was not part of the first Motus release. The agency has proposed no longer assigning MC Numbers, but says the change remains under consideration and will be addressed through a Notice of Proposed Rulemaking.

This is an important distinction because many carriers and brokers assumed that the Motus launch automatically meant MC Numbers disappeared. As of the current FMCSA guidance, they have not.

What is Motus?

Motus: USDOT Registration System is FMCSA’s modernized registration platform. FMCSA launched it to all users on May 19, 2026. It is designed to replace older registration tools with one system for applying for USDOT Numbers, operating authority, company updates, and other filings.

FMCSA says the larger modernization effort is intended to create a more centralized system for regulated entities and eventually replace parts of the legacy FMCSA Portal.

What changed when Motus launched?

• New and existing registrants began using Motus for registration actions.
• FMCSA began moving registration functions away from legacy systems.
• Users now create verified user profiles through Login.gov.
• Company accounts are managed through Motus.
• USDOT Numbers are central to entity identification.
• Motus displays suffixes that help identify registration and authority types.

What are USDOT Number suffixes?

FMCSA introduced suffixes in Motus to help identify entity types or registrations associated with a USDOT Number. Examples published by FMCSA include:

• C for property carrier operating authority
• B for broker operating authority
• F for freight forwarder authority
• P for passenger operating authority
• H for household-goods carrier authority
• V for private carrier

The suffixes are displayed in Motus for reference. FMCSA says they are not a vehicle-marking requirement.

Will a broker become USDOT Number plus “B”?

Inside Motus, the “B” suffix identifies broker operating authority associated with the USDOT Number. FMCSA’s long-term concept is to use the USDOT Number as the entity identifier while suffixes distinguish registrations or authority types.

That does not mean businesses should immediately replace all references to existing MC Numbers with a USDOT-B format. FMCSA has not yet completed the rulemaking that would phase out MC Numbers.

Will existing MC Numbers be converted into USDOT Numbers?

FMCSA says no. Existing MC Numbers will not simply be “replaced” by USDOT Numbers. MAP-21 requires regulated entities to have USDOT Numbers, and FMCSA has already been assigning USDOT Numbers to brokers, freight forwarders, and other entities that did not previously have one.

The agency is considering phasing out the MC Number as a separate identifier rather than converting each old MC Number into a new USDOT Number.

Why does FMCSA want to move away from MC Numbers?

FMCSA’s modernization effort is designed to simplify registration and reduce fragmented records. Historically, one company could be associated with several docket or authority numbers, while the USDOT Number provides a single entity identifier.

Using one entity identifier can make it easier to link operating authority, safety records, filings, insurance information, and company-account access to the same regulated business.

Does the MC Number still matter today?

Yes. Existing MC Numbers are still widely used in contracts, carrier packets, TMS records, factoring systems, broker onboarding, and industry searches. Until FMCSA completes a formal transition, brokers and carriers should continue preserving existing MC information alongside the USDOT Number.

Removing MC Numbers from internal systems too early could create unnecessary mismatches with older contracts, insurance records, customer files, or third-party databases.

What should freight brokers do now?

• Store both USDOT and MC identifiers where available.
• Use Motus and current FMCSA records for registration activity.
• Do not assume an MC Number is obsolete merely because Motus launched.
• Prepare systems to use the USDOT Number as the primary entity identifier.
• Monitor FMCSA rulemaking before changing contracts or workflows.
• Train staff on Motus suffixes and what they mean.

What should TMS providers do?

Transportation-management systems should avoid designing carrier records around the assumption that the MC Number will always be the primary identifier. The USDOT Number should be treated as the durable federal entity identifier, while authority types and legacy MC Numbers can be stored as related fields.

Systems should also be flexible enough to recognize Motus suffixes without treating the suffix as a new standalone company number.

Will vehicle markings change?

FMCSA states that the new Motus suffixes are not a vehicle-marking requirement. Motor carriers should continue following the applicable vehicle-marking regulations rather than adding authority suffixes simply because they appear in Motus.

How should brokers verify authority in the Motus era?

The safest approach is to verify the entity through its USDOT Number and review the operating-authority status associated with that entity. Do not rely only on an MC Number printed on a rate confirmation or carrier packet.

Carrier identity theft can involve copied MC and USDOT Numbers, so authority verification should be combined with independent contact verification and shipment-level driver and equipment checks.

How does this affect CargoGuard?

Freight-security platforms should be designed around durable entity identity rather than a single legacy number. CargoGuard can use carrier and shipment information together so brokers can compare registered carrier identity with the driver and equipment that appear for the load.

As FMCSA continues the Motus transition, USDOT-centered identity will become increasingly important for integrations and carrier matching. See how our driver verification software compares the driver and truck at pickup with the assigned carrier, how double brokering prevention works when a copied MC or USDOT Number is in play, and how the freight tracking API can carry USDOT-based carrier records into your TMS.

Scenario 1: broker sees an MC Number but no familiar legacy portal record

The broker should search current FMCSA systems using the USDOT Number and confirm the entity’s operating-authority status. Legacy systems may not display new Motus activity the same way they once did.

Scenario 2: a carrier packet lists only the MC Number

Request or locate the associated USDOT Number. The USDOT Number is increasingly important as FMCSA’s primary entity identifier and should be stored in the broker’s carrier record.

Scenario 3: TMS wants to remove the MC field

That may be premature. Existing contracts and historical records still use MC Numbers. A better design is to make USDOT the primary identity field while retaining MC Numbers as legacy or authority-related data until the formal transition is complete.

Frequently asked questions

Are MC Numbers gone in 2026?

No. FMCSA has proposed phasing them out, but says the change did not take effect with the first Motus release.

Is the USDOT Number becoming the main identifier?

Yes. FMCSA’s modernization plan centers entity identification on the USDOT Number.

What does the “B” suffix mean?

FMCSA identifies “B” as the Motus suffix for broker operating authority.

Should a broker stop using MC Numbers internally?

Not yet. Keep existing MC data while building systems around the USDOT Number as the primary federal identity field.

What readers should remember

MC Numbers are not gone. FMCSA has proposed eventually phasing them out, but the agency says that change was not included in the May 2026 Motus launch. The USDOT Number is becoming the central entity identifier, and Motus suffixes identify authority and registration types. Brokers and software providers should prepare for a USDOT-centered future without deleting legacy MC information too early.

Bottom line

Motus changed the registration system, but it did not instantly eliminate MC Numbers. Use the USDOT Number as the primary identity anchor, preserve existing MC information, learn the Motus suffixes, and wait for formal FMCSA rulemaking before treating MC Numbers as retired.

Why the transition matters for carrier onboarding

For years, many broker onboarding systems treated the MC Number as the fastest way to identify a for-hire carrier or broker. As FMCSA moves toward a USDOT-centered architecture, that assumption becomes less reliable. A modern onboarding workflow should start with the USDOT Number and then pull the authority and registration information associated with that entity.

This reduces duplicate records when a company has multiple authorities or legacy docket numbers and gives the broker a more stable identifier for integrations, tracking, billing, and fraud review.

What does Motus change for carrier packets?

Carrier packets should increasingly include the USDOT Number prominently. Existing MC Numbers can remain for historical continuity and matching with legacy systems. Brokers should avoid requiring a new registrant to produce an MC Number if FMCSA’s future rule eventually stops issuing them.

Software vendors should design forms so the MC field can become optional without breaking the record structure.

How should APIs handle the transition?

APIs should use the USDOT Number as the primary entity key and treat MC Numbers, suffixes, and authority types as attributes or related identifiers. This avoids rebuilding integrations later if FMCSA completes the phase-out.

Historical freight records should preserve the identifiers that were valid at the time of the load so disputes can still be reconstructed years later.

What if two records appear to share similar names?

Use the USDOT Number, legal business name, address, and authority data together rather than matching only by company name. Freight fraud often exploits similar names or copied branding. A single federal entity identifier makes it easier to distinguish businesses with nearly identical trade names.

How do suffixes help fraud prevention?

A suffix can quickly show the type of registration associated with the USDOT record. For example, a broker authority suffix and a property-carrier authority suffix describe different permissions. Operations teams can use that information as a quick reference, but should still review the underlying authority status rather than relying on a single letter.

Could a company have more than one suffix?

Yes. A company may hold more than one type of registration or authority. The suffix concept helps Motus represent those roles under one USDOT-centered identity. That is another reason the USDOT Number is more useful as the master record than any single legacy authority number.

What should accounting and factoring teams do?

Payment systems should preserve legacy identifiers during the transition because invoices, notices of assignment, and older carrier files may still reference MC Numbers. At the same time, teams should add or verify USDOT Numbers before changing remittance details. A fraudster can copy a legitimate MC Number, so the number by itself should not authorize a payment change.

How should contracts be updated?

New broker-carrier agreements can identify the carrier by legal name and USDOT Number and include the MC Number where applicable. Avoid drafting provisions that depend on the permanent existence of MC Numbers. Contract templates should be flexible enough to survive a formal FMCSA phase-out.

What happens to old contracts if MC Numbers are phased out?

An old MC Number will remain useful historical information even if FMCSA stops issuing new numbers. Companies should not rewrite or destroy old records merely because the federal identification model changes. Preserve the original identifiers and link them to the USDOT record.

How should fraud teams verify a company in 2026?

• Start with the USDOT Number.
• Confirm the legal business name.
• Review the authority types associated with the entity.
• Check current registration status.
• Confirm contact information independently.
• Preserve the legacy MC Number where applicable.
• Verify the actual driver and equipment for the load.

What not to do during the Motus transition

• Do not delete MC Numbers from historical data.
• Do not assume every company with no familiar MC display is unauthorized.
• Do not use suffixes as a substitute for checking authority status.
• Do not match carriers only by trade name.
• Do not wait for a final rule to make USDOT your primary internal identifier.

Why brokers should update training now

Carrier-sales and compliance employees may have spent years asking, “What is your MC?” Training should shift toward, “What is your USDOT Number, and what authority do you hold?” That language better reflects FMCSA’s current direction and prepares the team for the likely long-term transition.

What if FMCSA changes the plan?

Because the MC phase-out still requires rulemaking, the final details can change. Companies should monitor FMCSA announcements and the Federal Register. System changes should be designed to be reversible until the rule is final.

A migration plan for brokers and software teams

Companies do not need to wait for the final MC Number rule to modernize their data model. A sensible migration plan starts by identifying every system that treats MC Number as the primary key: TMS, CRM, carrier onboarding, accounting, fraud tools, data warehouse, customer portals, and APIs.

Next, add a verified USDOT field where it is missing and create a relationship between the USDOT entity and any legacy MC Numbers. Test reports and integrations using USDOT as the master identifier while continuing to display MC information where customers and staff still need it.

How to handle duplicate carrier records

Duplicate records are common when one system created a carrier by MC Number and another created the same company by USDOT Number. Use legal name, USDOT Number, address, and current authority information to merge records carefully. Preserve historical transaction links before deleting duplicates.

What customer-service teams should say

If a customer asks whether MC Numbers disappeared, the accurate answer is: FMCSA has proposed phasing them out, but the phase-out is not yet final. Motus launched with USDOT-centered registration, and the agency says a future rulemaking will address the MC Number change.

This wording avoids two common errors: telling customers that MC Numbers are already obsolete or telling them that nothing has changed. The registration architecture has changed, but the MC phase-out itself remains pending.

How this affects carrier search and compliance screens

Search interfaces should let employees find a company by USDOT Number, MC Number, or legal name, but the record returned should center on the USDOT entity. Display authority type and status clearly so users do not confuse a valid USDOT record with active broker or carrier authority.

How this affects fraud investigations

Fraud investigators should preserve all identifiers presented during a suspicious transaction. A copied MC Number may belong to a real company while the phone, email, or bank account belongs to the fraudster. Linking every identifier back to the verified USDOT entity makes it easier to spot those mismatches.

How to future-proof contracts and forms

Use language such as “USDOT Number and any applicable operating-authority identifiers” rather than hard-coding every process around the MC Number. Forms can still display MC where available while remaining usable if FMCSA later stops assigning new numbers.

What to watch next

• FMCSA’s Notice of Proposed Rulemaking on MC Number phase-out
• The effective date of any final rule
• Updates to Motus suffix displays
• Changes to public search tools
• Changes to insurance and authority data feeds
• Third-party vendor migration guidance

Assign someone on the compliance or product team to monitor these changes. A final rule could affect onboarding workflows, API schemas, customer instructions, and historical-data mapping.

What this means for freight-security platforms

Security platforms should be able to match a company across multiple identifiers during the transition. If a load was created using an MC Number but the live registration record is indexed primarily by USDOT Number, the system should connect both identifiers to the same entity instead of creating a second carrier profile.

That identity layer is especially useful when investigating fraud. The system can compare the registered USDOT entity, operating authority, contact information, driver, equipment, and shipment events without treating a copied legacy number as proof that the person communicating about the load is legitimate.

A simple internal transition policy

• Use USDOT Number as the primary company identifier.
• Retain MC Numbers as searchable legacy data.
• Display authority types from current FMCSA records.
• Teach staff the Motus suffixes.
• Do not remove MC fields until FMCSA finalizes the phase-out.
• Review all integrations before changing data formats.

This approach lets a brokerage modernize now without guessing the exact final rule. When FMCSA completes the transition, the company will already have the data structure needed to adapt.

Questions brokers are asking about MC Numbers

Will my current MC Number stop working tomorrow? No. FMCSA has not implemented the proposed phase-out. Should I stop asking for a USDOT Number? No; the USDOT Number is the core entity identifier and should be captured on every carrier or broker record. Should I delete old MC data? No; retain it for historical matching and contracts.

Will the suffix be painted on trucks? FMCSA says no. Motus suffixes are for registration reference, not vehicle marking. Will every company have the same suffix? No. The suffix reflects the entity’s registration or authority type, and an entity may hold more than one role.

Companies should keep a short change log for this transition: when USDOT became the primary internal identifier, when forms were updated, and when any future FMCSA final rule takes effect. That history will help explain older records and prevent employees from assuming historical data is wrong simply because it uses the old format.

That change log can also be shared with accounting, compliance, sales, and software vendors so every department uses the same identifier rules during the transition.

Keep vendor documentation aligned with the same policy so external systems do not reintroduce MC-first matching.

Primary sources: FMCSA: Will FMCSA Stop Issuing MC Numbers?; FMCSA Motus USDOT Number Suffixes; FMCSA Move Into Motus.