Intermodal Chassis Split Billing Dispute Mitigation Playbook: Per Diem, Chassis Usage, UIIA, and EIR Evidence

Not legal advice. This playbook is operational guidance. Interchange agreements, provider addenda, and tariffs change, and their exact terms control. Confirm current dispute windows and procedures in the agreement documents themselves and consult counsel for contested matters.

Three Charges, Three Billers, Three Clocks

Most chassis billing disputes start with confusion over which charge is which. A single import move can generate three distinct daily charges, each billed by a different party under a different document.

The terminology varies by port and contract. Some contracts use detention for the import side and per diem for the motor carrier interchange side. What matters for disputes is that each charge has its own start event, stop event, free time, and rate, and each must be tested separately. Demurrage and detention invoices from ocean carriers and terminals are subject to the FMC billing requirements at 46 CFR Part 541, covered in our guide to drayage demurrage dispute letter templates under OSRA 2022. Chassis usage charges from an equipment provider are generally governed by the interchange agreement and provider terms instead.

What a Chassis Split Is and Why It Generates Disputes

A chassis split move happens when the chassis and the container do not travel together for the whole cycle. The classic example: the terminal has no chassis on site, so the driver bobtails to an off terminal chassis depot, pulls a chassis, drives to the terminal to mount the container, delivers, and later returns the empty container to the terminal and the chassis to a depot that may be different from where it was picked up. Each leg adds miles, time, and gate transactions. Splits also happen in reverse on exports, and when a container is dropped at a customer and the chassis stays under it for days.

Splits generate disputes for predictable reasons. The chassis clock starts at the depot, hours or days before the container clock starts at the terminal. The chassis may be returned to a location the pool does not recognize as approved for that chassis, triggering extra days or repositioning charges. Gate systems at a depot and a terminal may not share data, so a provider's record may show a chassis still out when the carrier holds a receipt showing it was returned. And the carrier usually bears the cost of the extra split leg while the cause, a terminal chassis shortage, sits with someone else. Recovering split costs from customers depends on the carrier's own rate agreements, which is why split fees should be a defined accessorial in the TMS with evidence attached.

The Interchange Record Is the Source of Truth

Every transfer of equipment custody between a facility and a motor carrier produces an interchange record, often called an Equipment Interchange Receipt (EIR) or Trailer Interchange Receipt (TIR), and increasingly an electronic gate transaction record. A good receipt shows the container number, chassis number, seal number where applicable, the facility, the direction, the date and time, the truck and driver identifiers, and the condition notes. Those records, not driver memory and not the invoice, decide most disputes.

The matching discipline is simple to describe and hard to do by hand. For each container, pair its out gate with its in gate. For each chassis, pair its out gate with its in gate, even when those happen at different facilities. Then line up the pairs against each invoice line:

• Equipment number match - The container or chassis number on the invoice matches a receipt held by the carrier, including check digit validation for container numbers.
• Out time match - The invoice start date agrees with the out gate timestamp, after applying the stated free time.
• In time match - The invoice stop date agrees with the in gate timestamp, or with the first refused return attempt if the contract or tariff recognizes it.
• Custody match - The motor carrier billed is the carrier on the receipt. A frequent error is billing the wrong SCAC when one carrier handed equipment to another on a street turn or interline.
• Rate and free time match - The daily rate and free days on the invoice agree with the governing tariff, contract, or addendum in effect on the move date.

Example: a chassis usage invoice bills one chassis for 9 days. The carrier's receipts show the chassis left the depot on day 1 at 06:10 and was returned to a different approved depot on day 6 at 15:45. The invoice appears to be measured to the date the provider's system recorded the chassis at its home depot after repositioning, not to the carrier's return. With both receipts attached, the carrier disputes the days after the return. The chassis, per diem, and demurrage dispute estimator helps size disputed days and dollars like these before investing staff time.

Gate Transaction Timestamps: Getting Them Right

Timestamps are where clean disputes go wrong. Facilities record gate events in local time, telematics may record UTC, and the TMS may store the dispatcher's local time. A move that crosses midnight can shift a charge day if the systems disagree. Store every event with its original time zone or as UTC with the facility zone attached, and display both in the dispute package.

Use three independent sources where possible: the facility gate record or receipt, the ELD or telematics GPS position at the facility geofence, and the driver's mobile workflow event. When all three agree, the timestamp is very hard to challenge. When the facility record is missing, a GPS track showing the tractor inside the depot geofence, combined with a photo of the chassis and a trouble ticket number, may still persuade a provider to correct the record. Our ELD and EDI integration work connects terminal and depot status feeds, EDI 322 terminal operations events where available, and telematics geofences to the same container and chassis event table.

Refused Returns, Closures, and Appointment Failures

Many per diem disputes are not about wrong numbers. The numbers are right, but the carrier could not stop the clock. Terminals stop accepting a given ocean carrier's empties, appointment systems show no availability, a terminal closes for weather or labor reasons, or a depot refuses a chassis. Each of these events needs to be captured when it happens, with the date, time, facility, reason, and a reference such as a screenshot, a trouble ticket number, or the facility's published advisory. Drivers should log a refused return in the mobile app at the gate, not at the end of the shift. Dispatch should capture appointment search results when no slots exist.

For ocean carrier detention, the FMC interpretive rule at 46 CFR 545.5 considers whether charges serve their purpose of incentivizing the movement of equipment, and charges accruing while a return was not possible are a recognized point of contention. For chassis usage, whether the provider recognizes such events depends on its terms. In both cases, evidence captured in real time is what gives the argument weight.

The UIIA Dispute Path at a General Level

The Uniform Intermodal Interchange and Facilities Access Agreement, known as the UIIA and administered by the Intermodal Association of North America, is the standard interchange contract between participating motor carriers and equipment providers, including ocean carriers, railroads, and chassis providers. Providers attach addenda with their own rates, free time, and specific terms. The UIIA establishes procedures for invoicing per diem and related charges, for the motor carrier to dispute an invoice in writing within a defined period with supporting documentation, for the provider to respond within a defined period, and for escalating unresolved eligible disputes through a dispute resolution process administered under the agreement.

Because time limits and eligibility rules are set in the current agreement and the provider addenda and can change, this playbook does not quote section numbers or day counts. The operational rules are durable regardless:

• Know your windows - Load each provider's dispute and response windows into the TMS so every invoice gets a due date for dispute when it arrives.
• Dispute in writing, through the designated channel - Use the provider's portal or designated address, and keep the submission confirmation.
• Attach the evidence the first time - Matched receipts, refused return records, and advisories. An unsupported dispute is easy to deny.
• Track the response clock - Note when the provider's response is due and escalate promptly if it lapses or the denial is unsupported.
• Keep the file - Store the invoice, dispute, response, and outcome together for audit and for trend reporting.

The TMS Evidence Package

A dispute package should be producible in minutes from the TMS, not assembled by searching email. Design it around one record per invoice line, linked to the load, the container, and the chassis. Each record should hold the invoice image and extracted fields, the matched out and in interchange receipts for each asset, the telematics geofence events, the driver mobile events with photos, appointment and refused return records, applicable facility advisories, the tariff or addendum version in effect, the computed charge days by the carrier's records, the variance from the invoice, the dispute letter, and the outcome. Our document AI automation practice can extract fields from receipts and invoices so matching runs automatically, and SQL data mining finds orphaned receipts, unpaired gate events, and chassis that appear to be out with no open load.

The same package supports customer billing. When the carrier recovers split fees, chassis days, or per diem from a shipper or broker under its own agreement, the accessorial line should point to the evidence record so the customer sees the same receipts the carrier relied on. That linkage is a core part of transportation accounting integration, and it prevents the awkward situation of billing a customer for a charge the carrier is actively disputing.

Prevention Beats Disputes

The best dispute is the one never needed. Daily exception reports should list every chassis and container out past a threshold with no planned return, every split move without a recorded return location, and every return attempted at a location not approved for that equipment. Dispatch boards should show free time remaining for both the container and the chassis on the same screen. Monthly reporting by provider, facility, and dispute ground shows where disputes are won and lost and which operating changes, such as preferred chassis depots or earlier empty returns, cut charges at the source.

For the broader context of pool chassis, free time, and OSRA, see the related guide on intermodal chassis pool split billing and ocean port free time under OSRA.

Related practice areas for this work include ELD and EDI Integration, Document AI Automation, TMS Implementation, and SQL Data Mining. Each practice page describes scope, deliverables, and how an engagement starts with a short discovery call.

How Strong Tower Consulting Helps

Strong Tower Consulting helps drayage and intermodal carriers build interchange matching, timestamp normalization, invoice audit, and dispute workflows directly into the TMS, so evidence is captured during the move instead of reconstructed after the invoice arrives. Engagements start with a data inventory of current receipts, gate feeds, and invoices, move to a pilot on one port or provider, and expand with reports that dispatch, billing, and management can all read. Strong Tower Consulting, LLC and Exspeedite LLC are separately organized sister companies under common ownership. That separation keeps consulting advice vendor neutral and focused on the carrier operation.

To discuss your chassis exposure, providers, and systems, contact us or call 763-244-1373 and ask for Scott Elliott.

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