Each of these charges starts when a container, or the space it occupies, is kept past its free time. This guide follows one import container through the clock: what each charge means, who bills it at LA/Long Beach, how free time is counted, and what federal rules require on the invoice.
Free time is the number of days a container can stay before a charge applies. When it runs out, the charge depends on where the container is. Federal rules treat these charges as one category: 46 CFR 541.3 defines demurrage or detention as charges, including per diem charges, assessed by ocean common carriers, marine terminal operators or non-vessel-operating common carriers (NVOCCs) for the use of marine terminal space or shipping containers, not including freight charges.
Charged while the container stays at the marine terminal after free time ends.
In Maersk's published terms, import demurrage runs from the day the container is discharged until the full container leaves the terminal, and export demurrage runs from the day the full container is gated in until it is loaded on the vessel. The Port of Los Angeles tariff also uses the term wharf demurrage for a charge on merchandise that remains on the wharf after free time expires.
Charged while the steamship line's container is outside the terminal after free time ends, until the empty is returned.
In Maersk's terms, import detention runs from the day the full container leaves the terminal until the empty is returned to the agreed terminal, port or depot. COSCO's U.S. import detention rule starts on the day the full container is released to the consignee and continues until the empty is returned to the carrier's designated facility. For exports, Maersk's detention runs from the day the empty is picked up until it is gated back in.
The term used between equipment providers and trucking companies for equipment kept past free time.
The Uniform Intermodal Interchange and Facilities Access Agreement (UIIA), the standard contract between equipment providers and motor carriers, defines per diem as the charge paid when intermodal equipment is not returned by the end of the allowable free time, whether it is called per diem, a detention charge or something else. See the glossary entries for per diem and the UIIA.
Some terminals add their own daily fee for a loaded container that stays too long, on top of demurrage.
Maersk publishes separate demurrage and detention as well as combined demurrage and detention, and lists storage, the charge for using port, terminal or depot facilities, as a separate item. Check which method the steamship line's tariff or service contract uses before comparing invoices.
A single import container can produce bills from three different parties, each working from its own document.
Set by the line's tariff or service contract, or passed on by an NVOCC under the line's charge. Maersk's terms apply its published tariff unless the parties have agreed otherwise.
Port of Los Angeles Tariff No. 4, Section Seven, sets free time and wharf demurrage for merchandise on its wharves. Long Beach terminals refer to the Port of Long Beach tariff.
Under the UIIA, the equipment provider invoices the motor carrier for per diem when equipment is not returned by the end of the allowable free time.
"Terminal operators may assess free time provisions and demurrage storage charges, as filed in FMC terminal tariffs, for equipment occupying space on their terminals. When applicable, these charges are in addition to any charges herein for use of Carrier's equipment."
Evergreen Line, U.S. import demurrage and detention tariff, Note 13
"Each terminal will bill and collect their own demurrage according to their published tariff, except for the terminals listed below."
MSC USA, demurrage and detention schedule
At Long Beach Container Terminal (LBCT) and Total Terminals International (TTI), carrier demurrage follows each line's tariff, and it must be paid before the terminal releases the container. Both terminals ask that disputes be raised before payment; after payment, disputes go to the steamship line.
The same Port of Los Angeles tariff notes that equipment owned or leased by an ocean carrier is subject to demurrage or detention and free time under that carrier's own tariff. Federal invoice rules in 46 CFR 541 apply to demurrage and detention invoices issued by ocean common carriers, marine terminal operators and NVOCCs. They do not govern billing between ocean carriers and marine terminal operators.
Chassis usage is billed separately from container free time; the chassis split section of the chassis guide explains how chassis pools work at LA/Long Beach.
These names overlap, and they are not legally separate categories. A steamship line's detention and a UIIA per diem charge can describe the same kind of daily equipment charge, and 46 CFR 541.3 includes container per diem inside demurrage and detention. They are still separate bills, written on separate contracts. Per Diem and Demurrage Charges Decoded follows each bill.
Demurrage accrues while the loaded container sits at the marine terminal after free time. In the ordinary course at LA/Long Beach, that charge has to be paid before the terminal releases the container and the trucking company can pick it up. At LBCT and TTI, demurrage must be paid before release. That payment-before-pickup step is demurrage. It is not the detention charge that runs after the container has left, or the bill that arrives after the empty is returned.
Detention starts once the container leaves the terminal and runs until the empty is returned. Since 2022, the invoices reviewed for this guide have typically gone to the shipper, consignee or customer. That is observed practice. It is not a universal legal rule, and it is not evidence that every steamship line bills that way. Under the UIIA, section E.6 is the framework for per diem between an equipment provider and a motor carrier. The provider's addendum, not section E.6, sets the daily rate and the free time. Not every charge called per diem is a bill to a trucking company.
When a warehouse causes a late empty return, a trucking company may pass the per diem through to its customer at cost plus an administrative fee. That pass-through is a commercial agreement between the trucking company and its customer. Federal law does not require it, and the UIIA does not require that markup.
Federal billing rule, as of November 5, 2026. The Ocean Shipping Reform Act of 2022 directed the Federal Maritime Commission to decide which parties may be billed for demurrage and detention. From May 28, 2024 until September 23, 2025, former 46 CFR 541.4 limited in-scope invoices to the shipper for whose account the cargo moved, or the consignee. The U.S. Court of Appeals for the D.C. Circuit set that section aside in World Shipping Council v. FMC, and the FMC removed it effective December 29, 2025 (90 FR 60579). The removal notice says section 541.4 has no legal effect and that the other provisions of the rule remain in effect. Section 541.4 no longer imposes those categorical billed-party restrictions. Contract, tariff and consent still matter. In a May 26, 2026 compromise, the FMC described allegations that Maersk assessed detention against third parties who had not consented to be bound by its bill of lading, service contract or tariff. Maersk did not admit a violation. The 30-day invoice and dispute rules still apply where an invoice falls under Part 541. Who pays whom is the fuller note.
The last free day (LFD) is the final day of free time. Which days count toward it depends on the document that sets the free time. See the glossary entries for free time and last free day.
Port of Los Angeles
4 days
Port of Los Angeles Tariff No. 4, Item 720, sets free time for inbound containerized cargo from foreign ports at 4 days. Under Item 710, it starts after the container is discharged from the vessel.
Port of Long Beach
4 non-shaded days
The Port of Long Beach 2027 Free Time Calendar gives containerized inbound cargo four non-shaded days. Free time for each container starts at a fixed early-morning hour after that container is discharged.
Steamship Line
Set by tariff or contract
Detention free time is set by the line. Maersk describes free time as the period agreed between the carrier and the merchant, and applies its published tariff unless the parties have agreed otherwise.
Steamship lines do not all count the same way. Evergreen's U.S. import tariff lists 4 working days of free time at Los Angeles and Long Beach. COSCO's U.S. import detention rule counts working days, meaning days the facility is open and accepting pickups or returns, and its free time applies to containers, not chassis. Check whether the line counts calendar days or working days before setting a pickup date.
LBCT and TTI apply free time under the Port of Long Beach tariff and/or the individual line's tariff. Both count import free time from discharge. LBCT refers shippers to the Port of Long Beach Demurrage and Storage Free Time Calendar, and TTI refers to the end of free time as the Last Free Day. Under Port of Los Angeles Item 730, the Executive Director may shorten or extend free time.
Every charge on this page turns on a few dates: when the container is available, when it leaves the terminal and when the empty is returned. Each step below protects one of those dates.
Check that the container is released and free of holds before the pickup is booked. LBCT and TTI state that they are not responsible for delays caused by container holds, chassis shortages, traffic congestion or weather. The LA/Long Beach import checklist lists what to confirm, and the terminal map links each terminal.
Know which free time applies, whether weekends count at that terminal, and whether the line counts calendar or working days. Each day past the last free day can add the daily rate in that tariff.
Detention stops when the empty is gated in at the location the line designates, so confirm the return location before the empty leaves the consignee. The LA/Long Beach container depots guide and the glossary entry on empty return explain how returns work.
The FMC's interpretive rule at 46 CFR 545.5 states that detention charged when empty containers cannot be returned is likely to be found unreasonable. It also lists cargo availability, notice of availability and government inspections as factors the FMC may consider. Gate receipts such as the equipment interchange receipt (EIR) help document what happened.
Line free time is set by tariff unless the contract provides otherwise, so free time and detention terms can be part of contract negotiations.
Unloading the container at a warehouse in Carson and returning the empty can shorten the time the line's container is outside the terminal. The transload and warehousing page describes the service Whisk Freight Brokerage arranges, and Transload vs Drayage compares the two options.
Use the invoice requirements in the next section, and raise terminal demurrage disputes before payment at LBCT and TTI. The per diem dispute checklist walks through a per diem invoice line by line.
46 CFR Part 541 sets minimum invoice contents and billing deadlines for demurrage and detention invoices issued by ocean common carriers, marine terminal operators and NVOCCs.
Bill of lading numbers, container numbers, the port of discharge for imports, and the basis for why the billed party is liable for the charge (541.6(a)).
Invoice date and due date, allowed free time in days, free time start and end dates, container availability date for imports or earliest return date for exports, and the specific dates charged (541.6(b)).
Total amount due, the tariff rule, terminal schedule or service contract section on which the daily rate is based, and the specific rate or rates applied (541.6(c)).
A contact for questions and requests for mitigation, refund or waiver, a link or code to a public page describing what the billed party must provide, and the timeframes for requests and resolution (541.6(d)).
Statements that the charges are consistent with FMC demurrage and detention rules, including 46 CFR 545.5, and that the billing party's performance did not cause or contribute to the charges (541.6(e)).
Missing information
If an invoice omits any required minimum information, the billed party has no obligation to pay the charge (541.5).
30 days
The billing party must issue the invoice within 30 calendar days from the date the charge was last incurred. If it does not, the billed party is not required to pay the charge (541.7(a)).
30 days
The billing party must allow at least 30 calendar days from the invoice issuance date to request mitigation, refund or waiver, and must attempt to resolve a request within 30 calendar days of receiving it, or a later date both parties agree on (541.8).
The FMC's interpretive rule at 46 CFR 545.5 adds that demurrage and detention serve as financial incentives to promote freight fluidity, and that clear policies, dispute resolution processes and transparent terminology are factors in whether a practice is reasonable. For per diem invoices, the per diem dispute checklist covers the trucking side.
Demurrage is charged while a container stays at the marine terminal after free time ends. Detention is charged while the steamship line's container is outside the terminal after free time ends, until it is returned. Maersk's published terms, for example, run import demurrage from discharge until the full container leaves the terminal, and import detention from that gate-out until the empty is returned to the agreed terminal or depot.
The words overlap, and they are not legally separate categories. The UIIA treats a charge for equipment not returned by the end of free time as per diem whether it is called per diem, detention or something else. 46 CFR 541.3 includes container per diem in demurrage and detention, so not every per diem charge is a bill to a trucking company. Chassis per diem is outside Part 541. The bills still rest on different contracts: a steamship line tariff or service contract, and a provider's UIIA addendum.
Two parties can. The steamship line sets its demurrage in its tariff or service contract, and the marine terminal can charge its own demurrage under the port tariff and its schedule. Evergreen's tariff, for example, says terminal charges are in addition to the line's charges. At Long Beach Container Terminal (LBCT) and Total Terminals International (TTI), demurrage must be paid before the container is released.
It depends on the tariff. Port of Los Angeles Tariff No. 4 excludes Saturdays, Sundays and legal holidays from free time, except that weekends count for inbound containers when the terminal has announced its gates will be open for container delivery. LBCT and TTI count Saturdays and Sundays when the gate is open and exclude legal holidays. COSCO's U.S. import detention rule counts working days, meaning days the facility is open for pickups and returns.
Yes. Use the free days and the daily rates in the current steamship line tariff and the terminal schedule for that container. That is an estimate, not an invoice. The current tariff or service contract controls.
Under 46 CFR 541.6, the invoice must include the bill of lading and container numbers, the free time in days with its start and end dates, the container availability date for imports or earliest return date for exports, the dates charged, the tariff or contract rule and rate used, a contact for disputes, and certifications from the billing party. Under 46 CFR 541.5, missing required information eliminates the obligation to pay.
Under 46 CFR 541.8, the billing party must allow at least 30 calendar days from the invoice issuance date to request mitigation, refund or waiver, and must attempt to resolve the request within 30 calendar days of receiving it. Separately, LBCT and TTI ask that terminal demurrage disputes be raised before payment.
As of November 5, 2026, former 46 CFR 541.4 no longer limits the invoice to the contracting shipper or the consignee. Who receives a bill turns on the contract, the tariff and consent, and on the Shipping Act duties that still apply. The dated explanation is on Per Diem and Demurrage Charges Decoded.
Reviewed by Ray Wisniewski Jr., Founder and President. Updated November 5, 2026.
Primary sources, read through November 5, 2026. Tariffs and carrier terms change; the current tariff or service contract controls. For a specific container, send the shipment details or see how Whisk Freight Brokerage arranges container drayage at LA/Long Beach.
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