60 terms

The language of detention and demurrage.

Regulation, charges, terminals, equipment, documents and parties, each with why it matters when you dispute.

30-day issuance rule

Regulation

46 CFR § 541.7 requirement that a billing party issue a D&D invoice within 30 calendar days of the date the charge was last incurred; if it does not, the billed party is not required to pay.

The clock runs from the last day the charge accrued (typically the outgate for demurrage or the empty ingate for detention), not from the date the carrier's billing system produced the invoice. Late invoices are common on long-dwell containers, split shipments and charges that were re-rated after a correction. An NVOCC that is passing through a carrier or MTO charge has its own clock under § 541.7(b): it must issue within 30 calendar days of the issuance date of the invoice it received.

46 CFR Part 541 (Demurrage and Detention Billing Requirements)(Part 541)

Regulation

The FMC rule that sets what a D&D invoice must contain, when it must be issued, and how billed parties request relief. Published at 89 Fed. Reg. 14330 on February 26, 2024 and effective May 28, 2024.

Part 541 applies to invoices issued by ocean common carriers, NVOCCs and marine terminal operators. Its working sections are § 541.5 (missing information eliminates the obligation to pay), § 541.6 (the 20 minimum elements), § 541.7 (30-day issuance) and § 541.8 (relief requests and the billing party's 30-day resolution deadline). On September 23, 2025 the D.C. Circuit set aside § 541.4, the provision that limited invoice recipients to the contracting party or consignee, in World Shipping Council v. FMC, and the FMC later removed it from the CFR. The FMC has stated that the rest of Part 541 remains in effect, so every invoice audit still runs against §§ 541.5 to 541.8.

Beneficial cargo owner(BCO)

Parties

The importer or exporter that owns the goods being shipped, as opposed to an intermediary that arranges transport on its behalf.

BCOs ultimately pay most D&D, whether billed directly by the carrier or passed through by an NVOCC. Large BCOs usually hold their own service contracts and are billed directly; smaller ones often see charges only after a forwarder re-invoices them. In both cases the BCO is entitled to an invoice that meets Part 541, and its supply chain data (receiving schedules, dispatch records) often holds the evidence for a dispute.

Bill of lading(B/L)

Documents & data

The transport document issued by the carrier (or an NVOCC, as a house B/L) that evidences the contract of carriage, receipt of the cargo and, for a negotiable B/L, title to the goods.

The B/L number is the first required element of a D&D invoice under § 541.6(a)(1), and it is how the billed party ties a charge to a shipment, a contract and a party. Forwarded shipments have a master B/L from the carrier and a house B/L from the NVOCC, and invoices that cite only the master number can be hard for the importer to match. The B/L also shows the consignee and notify parties, which bears on who the proper billed party is.

Billed party

Parties

Under 46 CFR § 541.3, the person receiving a demurrage or detention invoice who is responsible for paying any incurred charge.

The billed party holds the dispute rights: at least 30 days from issuance to request mitigation, refund or waiver under § 541.8, no obligation to pay an invoice missing required information under § 541.5 or issued late under § 541.7, and the ability to submit a charge complaint under 46 U.S.C. § 41310. The former § 541.4 limit on who could be billed was set aside by the D.C. Circuit in September 2025, so whether a recipient is the right party now turns more on the contract, tariff and B/L, while the invoice must still state the basis for billing that party under § 541.6(a)(4).

Billing party

Parties

Under 46 CFR § 541.3, the ocean common carrier, marine terminal operator or non-vessel-operating common carrier that issues a demurrage or detention invoice.

The billing party carries the Part 541 obligations: include the 20 elements, issue within 30 days of the last incurred date, certify consistency with FMC rules and that its own performance did not contribute, and resolve relief requests within 30 days of receipt. Identifying the billing party correctly also determines which tariff or schedule applies and where a relief request must go.

Billing party certifications

Regulation

The two statements 46 CFR § 541.6(e) requires on every D&D invoice: that the charges are consistent with FMC D&D rules, and that the billing party's performance did not cause or contribute to the charges.

The certifications are short, but their absence is a complete defense under § 541.5, and their presence creates something to test. If the carrier certifies that its own performance did not contribute and the evidence shows a vessel delay, a late discharge or a terminal that refused the empty, the certification itself becomes part of the dispute. Audits flag invoices that carry boilerplate certifications on charges that overlap documented terminal disruptions.

Cargo cutoff

Terminal & port

The last date and time a terminal will receive a loaded export container for a specific vessel departure.

The window between the ERD and the cutoff is the only time an export load can be delivered. When terminals shorten that window or move the cutoff earlier, exporters either miss the vessel or hold loaded boxes on the street, and detention follows. Ag exporters with large numbers of loads per booking feel this most. Terminal receiving notices and vessel schedule changes for the booking are the documents that show the window was not under the shipper's control.

Charge complaint

Regulation

A complaint submitted to the FMC under 46 U.S.C. § 41310 alleging that a charge assessed by a common carrier violates 46 U.S.C. § 41104(a) or § 41102(c).

OSRA 2022 created the charge complaint as a lighter path than a formal Shipping Act complaint. For detention and demurrage charges, the common carrier bears the burden of establishing that the charge was reasonable, and the Commission can order a refund or waiver. Charges invoiced before June 16, 2022 are excluded. The complaint is submitted by the billed party or its counsel; ATAHSKIA compiles the dossier (invoice, relief request, the carrier's response and the evidence timeline) for the billed party to submit.

Chassis

Equipment

The wheeled frame a container rides on for road transport between the terminal, the customer and the return location.

No chassis, no move. In most US port markets chassis are supplied by intermodal equipment providers or pools rather than by ocean carriers, and a chassis shortage can strand an available container in the yard as surely as a closed gate. Chassis daily use charges are billed separately from container D&D, but chassis unavailability on the days billed is relevant evidence when disputing demurrage or detention for the container itself.

Chassis pool

Equipment

A shared fleet of chassis available to multiple motor carriers at a port or rail market, operated by one or more intermodal equipment providers under common usage terms.

Pools reduce the need for each trucker to own chassis, but pool supply can run short during volume surges and pool rules can restrict where chassis may be picked up or dropped. When a pool had no chassis at the location serving a terminal, truckers could not pull containers that were otherwise available. Pool status notices and the trucker's failed pickup attempts help show the delay was outside the billed party's control.

Chassis split

Equipment

A move where the chassis must be collected from, or returned to, a different location than the container, adding a separate trip to the drayage.

Splits cost the trucker time and extra trips, and when a terminal has few or no chassis on site they can push pickups past the last free day. Split charges themselves are trucking accessorials, not ocean D&D, but the frequency and timing of splits at a terminal help explain why containers sat longer than free time. Dispatch logs showing the chassis location for each move belong in the evidence file.

Combined D&D free time

Charges

A free time arrangement where one pool of days covers both time at the terminal and time out with the customer, instead of separate demurrage and detention allowances.

Combined free time is convenient for importers who pull containers quickly, but it makes invoices harder to check. When terminal days and street days share one clock, a delay at the terminal (a hold, a lack of appointments) eats into the time the consignee needs to unload and return the empty. Audits split the combined period back into its terminal and street segments using gate events, so that blocked days on either side can be identified and disputed.

Related: Free time, Demurrage, Detention

Consignee

Parties

Under 46 CFR § 541.3, the ultimate recipient of the cargo: the person to whom final delivery is to be made.

The consignee is commonly the party billed for import demurrage and detention. In forwarded and multi-party shipments the consignee on the master B/L, the house B/L and the customs entry may differ, which affects who should have received the invoice and who has standing to dispute it. Matching the billed entity to the B/L parties is an early step in every audit.

Container availability date

Terminal & port

The date an import container was actually available for pickup: discharged, released by the carrier and customs, free of holds and accessible at the terminal. Required on import invoices by 46 CFR § 541.6(b)(6).

Availability is the single most disputed date in import D&D. Discharge is not availability: a container can sit buried in the yard, on a customs or USDA hold, or behind a carrier freight hold for days after it comes off the vessel. If free time started before true availability, every following day is shifted and the invoice overstates charges. An invoice that omits the availability date entirely is missing a required element under § 541.6.

Container number

Documents & data

The unique identifier on every intermodal container under ISO 6346: a three-letter owner code, an equipment category letter (U for freight containers), a six-digit serial number and a check digit.

Every D&D invoice must list the specific containers billed under § 541.6(a)(2). The check digit makes typos detectable, and audits validate it before matching the container to gate and milestone events. Invoices that roll several containers into one line, transpose digits, or bill a container that belongs to a different B/L are routine exceptions.

Delivery order

Documents & data

The instruction from the consignee or its customs broker to a trucker, and the release from the carrier to the terminal, authorizing a specific container to be picked up.

Delays between freight release, customs release and the delivery order reaching the trucker explain many lost free days. When the carrier released late or the release was not reflected in the terminal system, the days in between are a dispute ground. Time stamps on the release messages and the delivery order help separate the consignee's own delays from blocks outside its control.

Demurrage

Charges

A daily charge for a container that stays inside the marine terminal after its free time ends, billed by the ocean carrier or the marine terminal operator.

Demurrage is meant to clear terminal space, so it only makes sense on days the cargo could actually leave. The dispute questions are almost always about dates: when the container became available (not merely discharged), whether holds or a lack of appointments blocked pickup, and whether the billing started after the last free day rather than on it. Part 541 defines demurrage and detention to include any such charge by a carrier, NVOCC or MTO related to the use of terminal space or containers, whatever the invoice calls it.

Detention

Charges

A daily charge for keeping a carrier's container outside the terminal beyond the allowed free time, typically running from outgate until the empty (or export load) is returned.

Detention is where terminal operations and trucking collide. A trucker can be ready to return an empty and still be refused because the terminal will not take that carrier's equipment, has no appointments, or demands a dual transaction. Each of those days is a candidate for an incentive-principle dispute if the refusal is documented. Detention disputes also turn on the correct return location: if the carrier redirected empties to a depot that was itself full, the evidence trail needs both locations.

Drayage carrier

Parties

A motor carrier that moves containers by truck between marine terminals, rail ramps, warehouses and empty depots.

Draymen see terminal conditions first and often receive per diem invoices directly under their interchange agreements. Their dispatch records, gate transaction history and appointment logs are frequently the best evidence an importer has. Because carriers sometimes bill truckers and importers for the same equipment days, the drayage carrier and the BCO benefit from sharing evidence and agreeing on who disputes what.

Dual transaction

Terminal & port

A terminal requirement that a trucker pair two moves in one visit, most often returning an empty only when also picking up a load, or picking up a load only when also dropping a container.

Dual transaction rules help terminals manage volume, but they can make an empty return impossible for a trucker who has no matching pickup that day. Detention billed for days when the only way to return an empty was to have another load at the same terminal is a recognized dispute pattern in port congestion. Evidence includes the terminal's posted dual transaction notice and the trucker's records of attempted returns.

Earliest return date(ERD)

Terminal & port

The first date a terminal will accept a loaded export container for a given vessel. Required on export invoices by 46 CFR § 541.6(b)(7).

Exporters pick up empties, load them and then often cannot deliver because the receiving window has not opened. Detention keeps running while the full container waits on a chassis outside the terminal. When the ERD moves later (a vessel delay or a schedule change), the exporter is charged for time it had no way to use. Comparing the ERD in force when the empty was picked up with the final ERD is the starting point of most export detention disputes.

EDI 310 (Freight Receipt and Invoice, Ocean)(EDI 310)

Documents & data

The ANSI X12 transaction set used to transmit ocean freight receipt and invoice details, including charges billed against a shipment.

Some carriers and NVOCCs send D&D charges electronically rather than as PDF invoices. Electronic delivery does not relax Part 541: the 20 elements and the certifications must still be present and accessible, because the rule covers any statement of charges printed, written or accessible online. Parsing 310 data directly lets an audit catch missing elements without waiting for a PDF.

EDI 315 (Status Details, Ocean)(EDI 315)

Documents & data

The ANSI X12 transaction set carriers use to send container status events such as vessel departure and arrival, discharge, availability, outgate, empty return and holds.

The 315 stream is the backbone of milestone reconciliation. Lining up 315 events with the dates on an invoice shows whether free time started at availability, whether billing stopped at the empty return and whether holds overlapped the charged days. Gaps and late-arriving events are common, so 315 data is strongest when cross-checked against terminal records rather than used alone.

EDI 322 (Terminal Operations and Intermodal Ramp Activity)(EDI 322)

Documents & data

The ANSI X12 transaction set terminals and rail ramps use to report container activity such as ingate, outgate, load and discharge.

Where the 315 reflects what the carrier recorded, the 322 reflects what the terminal or ramp recorded. Differences between the two are useful in disputes: a terminal outgate that preceded the carrier's recorded date, or an ingate the carrier never booked, can each move the billing period. Access to 322 data usually comes through terminal, rail or visibility provider feeds.

Empty depot

Equipment

An off-dock container yard where carriers direct empties to be returned, stored and inspected instead of the marine terminal.

When carriers redirect returns to depots, detention ends at the depot ingate, so the depot's receipt time matters as much as any terminal record. Depots have their own hours and capacity limits, and a redirect to a depot that was full or closed leaves the trucker with nowhere to go. The return instruction in force on the day, the depot gate record and any refused attempt are the documents to keep.

Empty return restriction

Terminal & port

A terminal or carrier notice that a location will not accept empties for some or all carriers, equipment types or sizes on a given day, sometimes redirecting returns to another terminal or depot.

When the designated return location refuses an empty, the trucker cannot stop the detention clock, which is exactly the situation the FMC's incentive principle describes. These restrictions are typically published as daily notices that change at short notice, so evidence disappears quickly. A defensible file shows the restriction notice, any failed return attempt (gate trouble ticket or turned-away record) and the date the empty was finally accepted.

Equipment interchange receipt(EIR)

Documents & data

The gate record created when equipment changes hands between a terminal or depot and a motor carrier, showing the container, chassis, condition, date and time.

The EIR is the cleanest proof of when detention started and stopped. A return EIR with a time stamp before the carrier's recorded return date, or an outgate EIR later than the carrier's start date, translates directly into fewer billable days. Truckers and importers should store EIRs per container in a place the audit team can reach, not only in the dispatcher's inbox.

Federal Maritime Commission(FMC)

Parties

The independent federal agency that regulates ocean transportation in the US foreign commerce, including carriers, marine terminal operators and ocean transportation intermediaries.

The FMC wrote Part 541 and the § 545.5 interpretive rule, receives charge complaints under 46 U.S.C. § 41310 and can order refunds or waivers of unreasonable D&D. It also publishes guidance and decisions that shape how carriers respond to relief requests. Complaints are submitted to the Commission by the billed party or its counsel.

Forty-foot equivalent unit(FEU)

Equipment

A 40-foot container, equal to two TEU. Includes standard 40-foot and 40-foot high cube boxes.

Most US import volume moves in 40-foot and 40-foot high cube containers, and tariff rate tables usually list separate daily rates by container size and type. A frequent invoice error is a 20-foot rate applied to a 40-foot box or the reverse, or a special-equipment rate applied to a standard container. The container number and size-type code on the invoice should match the B/L and the gate record.

Free time

Charges

The number of days a container may sit at the terminal (for demurrage) or stay out with the customer (for detention) before charges start, set by the carrier's tariff, a service contract or the MTO's terminal schedule.

Free time must appear on the invoice as the allowed number of days plus a start and end date, under § 541.6(b)(3) to (5). The most common error is starting free time at discharge instead of at availability, which quietly consumes days the importer never had. Service contracts often grant more free time than the published tariff, and invoices that bill against the tariff default are a recurring source of credits. Check whether free time is counted in calendar days or working days, and whether weekends and holidays are excluded under the applicable rule.

Gate closure

Terminal & port

A period when a terminal's truck gates are shut to some or all transactions, whether scheduled (holidays, shift changes) or unplanned (weather, labor events, system outages, congestion).

Days or shifts when the gate was closed are among the clearest incentive-principle grounds, because neither pickup nor return was possible. The evidence is the terminal's own advisory or gate schedule for that day, archived at the time. Partial closures need more care: a gate that was open for exports but closed for empty returns supports a detention dispute but not a demurrage one.

Hold (customs, freight, USDA, terminal)

Terminal & port

A flag on a container that blocks its release from the terminal until cleared, placed by CBP or another government agency, by the carrier (for example unpaid freight), or by the terminal (for example unpaid terminal fees).

Who placed the hold decides how the days are argued. Government inspection holds are one of the situations the FMC's incentive principle addresses, and days under a hold the consignee could not clear are a natural dispute ground. A carrier freight hold the consignee caused by late payment is a weaker argument, while a freight hold placed in error is a strong one. Recording hold placement and release timestamps per container, rather than per shipment, keeps the argument precise.

Incentive principle

Regulation

The FMC's interpretive rule at 46 CFR § 545.5 (2020), under which the reasonableness of D&D is assessed by whether the charge serves its purpose of incentivizing the movement of cargo and equipment.

If cargo or equipment could not be moved, a charge cannot incentivize anything. The interpretive rule names the situations the Commission focuses on: closed or congested terminals, no available appointments, empty return refusals and government inspections or holds. In a dispute, the incentive principle is argued with evidence, not adjectives. Terminal advisories, appointment system screenshots, gate transaction records and hold release timestamps for the exact days billed are what turn the principle into a credit.

Intermodal equipment provider(IEP)

Equipment

A company that owns or manages chassis and offers them to motor carriers under interchange agreements, either directly or through pools.

IEPs bill chassis use separately from container D&D, and they are not billing parties under Part 541 for those chassis charges. Their records still matter: chassis availability and outage notices from the IEP serving a terminal can show why a trucker could not move an available container on the days billed.

Just and reasonable practices

Regulation

46 U.S.C. § 41102(c), which requires common carriers, ocean transportation intermediaries and marine terminal operators to establish, observe and enforce just and reasonable regulations and practices relating to receiving, handling, storing or delivering property.

Section 41102(c) is the legal hook for the incentive principle and one of the two grounds a charge complaint can rest on. A D&D practice that bills days when the cargo could not be retrieved or the empty could not be returned is the classic § 41102(c) argument. The billed party does not have to show bad intent; the question is whether the practice, as applied to those containers on those dates, was reasonable.

Last free day(LFD)

Charges

The final day of free time; charges should begin on the following day.

Dispatchers plan around the LFD, and a wrong LFD on the terminal or carrier system can push a whole week of pickups into chargeable days. Invoices sometimes bill from the LFD itself (an off-by-one error) or recalculate the LFD after a re-rate without telling the consignee. Capturing the LFD shown in the terminal portal or EDI feed on the day of availability gives the billed party a contemporaneous record to compare with the end date of free time printed on the invoice.

Marine terminal operator(MTO)

Parties

A company that operates a marine terminal providing wharfage, dock, warehouse or other terminal facilities to ocean carriers and cargo interests.

MTOs are billing parties under Part 541 when they issue demurrage or storage invoices, and they control many of the facts that decide D&D disputes: gate hours, appointment supply, empty receiving and holds. In US ports, import demurrage may be billed by the carrier or directly by the terminal depending on the port and arrangement, so the audit has to identify who actually issued each invoice before applying the rules.

Minimum invoice information (20 elements)

Regulation

The 20 data elements that 46 CFR § 541.6 requires on every D&D invoice, grouped as identifying, timing, rate, dispute and certification information.

Under § 541.5, an invoice that omits any required element eliminates the billed party's obligation to pay the charge. That makes the element check the fastest and least argumentative dispute ground: the billed party does not need to prove the charge was unfair, only that the invoice is incomplete. The elements most often missing in practice are the container availability date, the earliest return date on export bookings, the specific rule or contract section relied on, and the two billing party certifications.

Non-vessel-operating common carrier(NVOCC)

Parties

A common carrier that issues its own bills of lading and contracts with shippers for ocean transport but does not operate the vessels, buying space from VOCCs instead.

NVOCCs are both billed parties (receiving D&D invoices from carriers and terminals) and billing parties (re-invoicing their own customers). Part 541 gives them specific timing rules in § 541.7(b) and (c). An NVOCC that disputes upstream invoices promptly protects its margin and its client relationships; one that pays and re-bills without checking absorbs every charge its customer successfully disputes.

NVOCC pass-through invoice

Regulation

A D&D invoice an NVOCC issues to its own customer to pass on charges it was billed by an ocean carrier or MTO, governed by the NVOCC rules in 46 CFR § 541.7(b) and (c).

The NVOCC sits on both sides of the rule. As a billed party it can dispute the carrier's invoice; as a billing party its own invoice to the shipper must carry the 20 elements and meet its own 30-day deadline, which runs from the issuance date of the invoice it received. When the NVOCC's customer disputes the charge, § 541.7(c) lets the NVOCC notify the upstream carrier or MTO, which must then allow the NVOCC an additional 30 calendar days to dispute the charge itself. Forwarders who pass charges through without checking the upstream invoice end up defending a bill the carrier never had a right to collect.

Ocean Shipping Reform Act of 2022(OSRA 2022)

Regulation

Federal statute (Pub. L. 117-146, signed June 16, 2022) that amended the Shipping Act and directed the Federal Maritime Commission to set rules for detention and demurrage billing.

OSRA 2022 is the root of almost every modern D&D dispute. It created the charge complaint process at 46 U.S.C. § 41310, placed the burden of establishing reasonableness of D&D charges on the common carrier, and required the FMC to write the minimum invoice information rule that became 46 CFR Part 541. Charges invoiced before June 16, 2022 fall outside the charge complaint process, so the invoice date on older bills decides which tools are available to the billed party.

Ocean transportation intermediary(OTI)

Parties

The Shipping Act category covering NVOCCs and ocean freight forwarders, licensed or registered with the FMC.

An ocean freight forwarder books cargo and prepares documents for shippers but does not issue its own B/L, while an NVOCC does. The distinction matters for D&D: Part 541 lists NVOCCs as billing parties, so an NVOCC's re-invoice must meet the rule, whereas a forwarder relaying a carrier's invoice is passing on the carrier's bill. Knowing which role an intermediary played on a shipment tells you whose invoice you are disputing.

Per diem

Charges

A daily equipment use charge, usually billed by the ocean carrier to the motor carrier that interchanged the container, for equipment held past free time. Often used interchangeably with detention.

Per diem is commonly billed to drayage carriers under the equipment interchange terms they accept, such as the UIIA, and then re-billed up the chain to the importer or NVOCC. The FMC's D&D definition expressly includes per diem, so a per diem invoice from a carrier is a D&D invoice subject to Part 541. A trucker disputing per diem needs gate transaction records, appointment system history and the terminal's empty receiving notices for each day billed.

Reefer container

Equipment

A refrigerated container with its own cooling unit that must be plugged into power at the terminal or run on a generator set (genset) when on the road.

Reefers usually carry higher D&D rates than dry containers, and terminals may add separate power or monitoring charges while a reefer waits for pickup. Perishable importers and meat and produce exporters run tighter schedules, so a single day of blocked access can be costly. Check that the invoice applies the reefer rate only to reefer equipment and that any plug-in charges are not duplicating storage for the same days.

Relief request (mitigation, refund or waiver)

Regulation

A billed party's request under 46 CFR § 541.8 to reduce, refund or waive a D&D charge, which the billed party may make for at least 30 calendar days after the invoice is issued.

The relief request is the first formal dispute step and it has two clocks. The billed party must get at least 30 calendar days from issuance to submit, and the billing party must resolve the request within 30 calendar days of receipt unless both sides agree otherwise. A well-built request names the invoice, cites the specific Part 541 subsection or incentive-principle ground, and attaches the evidence. Tracking the billing party's resolution deadline matters because an unanswered or unsupported denial is the usual starting point for a charge complaint.

Rolled booking

Terminal & port

An export booking the carrier moves to a later vessel than the one originally confirmed, often after the shipper has already picked up and loaded the empties.

A roll resets the ERD and cutoff while the shipper's containers are already out on the clock. Detention billed for days created by the carrier's own roll is a direct conflict with the § 541.6(e) certification that the billing party's performance did not cause or contribute to the charges. Keep the original booking confirmation, the roll notice and the new vessel's receiving dates together for each affected container.

Service contract

Documents & data

A confidential written contract between a shipper (or NVOCC) and an ocean common carrier covering a minimum volume over a period, filed with the FMC and often setting negotiated free time and D&D rates.

Service contract free time and rates override the carrier's published tariff for covered shipments. Part 541 requires the invoice to identify the service contract number and section when that is the source of the charge (§ 541.6(c)(2)). A recurring audit finding is an invoice that applies the tariff default to cargo moving under a contract with longer free time.

Shipper-owned container(SOC)

Equipment

A container owned or leased by the shipper rather than supplied by the ocean carrier, identified by an owner code that is not the carrier's.

Carrier detention is a charge for using the carrier's equipment, so it should not appear on a SOC container. Terminal storage can still apply while a SOC box sits on terminal. Invoices that bill carrier detention on SOC equipment usually stem from a booking or equipment code error, and the container's owner prefix plus the B/L notation are normally enough to resolve them.

Street turn

Equipment

Reusing an empty import container directly for an export load without first returning it to the terminal or depot, normally with the ocean carrier's approval.

Street turns cut empty miles and can stop detention sooner, because the box is reassigned to an export booking instead of waiting for a return slot. If the carrier approved a street turn, detention on the import side should end at the approval or interchange date for the new move, not when the box eventually comes back as an export. Approval records and interchange receipts are the evidence that the import billing period was closed.

Tariff rule and terminal schedule

Documents & data

The published carrier tariff rule or MTO terminal schedule that sets free time, D&D rates and conditions when no service contract term applies.

Every D&D invoice must cite the specific rule it relies on: the tariff name and rule number, the terminal schedule, or the service contract number and section. Without that citation the billed party cannot check the rate or free time, and the invoice is missing a required element under § 541.6(c)(2). With it, the audit compares the billed free time, rate tiers and exclusions (weekends, holidays) to the published text in force on the billed dates.

Terminal appointment system

Terminal & port

The booking system a terminal uses to control truck arrivals for import pickups, export deliveries and empty returns, usually by time window and transaction type.

An available container is not retrievable if no pickup appointment can be booked before the last free day. Appointment scarcity is one of the situations the FMC's incentive principle singles out, but it is also the hardest to prove after the fact because availability changes by the hour. Dated screenshots or system exports showing no open slots for the transaction type, terminal and dates in question are the evidence carriers and MTOs respond to.

Terminal operating system(TOS)

Terminal & port

The software a container terminal uses to plan yard positions, vessel operations and gate transactions, and the system of record for when a container was discharged, made available, gated out or received.

Carrier invoices are built from carrier systems; terminal reality lives in the TOS. When the two disagree (a container shown available by the carrier but still under a terminal hold, or an empty refused at the gate that the carrier never recorded) the TOS record is usually the stronger evidence. Many terminals expose TOS status through a public container lookup or portal, and capturing that status on the day it applies avoids relying on a reconstruction months later.

Terminal storage charge

Charges

A charge billed by a marine terminal operator for cargo or containers occupying terminal space past free time, often labeled storage rather than demurrage.

Labels do not change the rules. Part 541 defines demurrage and detention as any charges by an ocean carrier, NVOCC or MTO related to the use of marine terminal space or shipping containers (other than freight), so an MTO storage invoice is held to the same 20 elements and 30-day issuance deadline as a carrier demurrage invoice. Importers sometimes receive both a carrier demurrage bill and a terminal storage bill for the same days, which is worth flagging for review.

Tiered daily rate

Charges

A D&D rate structure where the per-day charge steps up after set numbers of chargeable days, as published in the applicable tariff rule, service contract or terminal schedule.

Because rates escalate, every wrongly billed day early in the period pushes later days into a higher tier. Correcting the availability date or removing blocked days therefore reduces the invoice by more than the simple day count suggests. Part 541 requires the invoice to show the specific rate or rates applied and the rule they come from (§ 541.6(c)), so the tiers on the invoice can be checked against the published source.

Traffic Mitigation Fee(TMF)

Charges

A per-container fee administered by PierPass and assessed on cargo moving through the marine terminals at the Ports of Los Angeles and Long Beach to fund extended terminal gate hours.

The TMF is a per-move fee, not a time-based charge, so it is not something to dispute on the basis of dwell days. It matters in D&D work for two reasons. It shows up in the same import cost lines, so audit teams need to keep it separate from demurrage when measuring recoveries, and the gate schedules it funds define when a San Pedro Bay terminal was actually open for pickups and returns on the days billed.

Truck detention (driver wait time)

Charges

A motor carrier accessorial charge for driver and truck waiting time at a pickup or delivery location, separate from ocean container detention.

The shared word causes real confusion in AP departments. Driver wait time is billed by the trucking company under its rate agreement with the shipper or broker; it is not issued by an ocean carrier, NVOCC or MTO, so Part 541 does not govern it. Keeping the two apart matters for recovery reporting and for evidence: long terminal turn times that drive truck detention are often the same events that support an incentive-principle dispute on the ocean carrier's detention invoice.

Twenty-foot equivalent unit(TEU)

Equipment

The standard measure of container volume, where one 20-foot container equals one TEU and one 40-foot container equals two.

Port volumes, carrier capacity and most D&D benchmarks are stated in TEU, but D&D is billed per container, not per TEU. A 40-foot box usually carries one daily charge at its own rate, so converting TEU volume to container count matters when estimating exposure. ATAHSKIA plans are banded by annual TEU because it tracks how many invoices a team has to check.

Uniform Intermodal Interchange and Facilities Access Agreement(UIIA)

Documents & data

The standard interchange agreement, administered by the Intermodal Association of North America (IANA), that sets the terms under which motor carriers take and return intermodal equipment from participating providers.

For drayage carriers, the UIIA and each provider's addendum govern free time, per diem terms and the provider's own dispute process for equipment. Per diem billed by an ocean carrier is also a D&D charge under Part 541, so a trucker can test the invoice against the 20 elements and the 30-day issuance rule as well as against the interchange terms. Keeping the applicable addendum version on file avoids arguments about which terms applied on the billed dates.

Vessel-operating common carrier(VOCC)

Parties

An ocean common carrier that operates the vessels carrying cargo in US foreign trade; the ocean carrier in the everyday sense.

VOCCs issue most container demurrage and detention invoices and are billing parties under Part 541. For a charge complaint under 46 U.S.C. § 41310, the common carrier bears the burden of establishing that its D&D charge was reasonable. VOCC billing practices vary widely, which is why ATAHSKIA scores each carrier on invoice compliance and dispute response in a customer's own book rather than relying on reputation.

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