Key takeaways
- Demurrage accrues when a full container sits inside the terminal beyond free time; detention accrues when the container — full or empty — sits outside the terminal beyond free time. They are separate clocks with separate tariffs, and a single delayed shipment routinely triggers both.
- Free time is commonly 3–7 calendar days for demurrage and 3–5 days for detention as a carrier default, but it is negotiable at booking — committing volume and securing 14–21 combined free days upfront is the single highest-leverage mitigation for resin importers.
- Charges are tiered and escalate by bracket, so a stalled FCL parcel can quietly add a four- to five-figure sum to landed cost; rates vary by carrier, port, and equipment, so model them as a real line, not a footnote.
- Root causes for resin parcels are predictable — slow customs/REACH or import documentation, delayed delivery orders, financing or original B/L delays, plant or warehouse congestion, and chassis or haulier shortages — and every one is addressable before the vessel berths.
Demurrage and detention are the two charges that turn a clean resin import into a margin problem after the deal is done. They do not show up in the price negotiation, the MFI spec, or the certificate of analysis — they accrue silently, one day at a time, on the back end of the supply chain, and they are almost always avoidable. For a buyer moving full-container-load (FCL) parcels of HDPE, PP raffia, or PVC, a fortnight of demurrage on a modest shipment can erase the freight saving that justified the route in the first place.
The mechanics are simple once separated. Every container ships with free time — a window during which it can sit at the terminal or off-port without penalty. Miss that window and the meter starts. The critical distinction, which buyers conflate constantly and pay for, is where the box is sitting when the clock runs: inside the terminal, or outside it.
Demurrage is the charge for a full container occupying space inside the port terminal beyond its free time. You imported the goods, the vessel discharged, and the box is now squatting in the yard waiting to be collected. The terminal wants its slot back; the carrier bills you per container per day until you gate it out.
Detention is the charge for a container being held outside the terminal beyond its free time. You collected the full box, hauled it to your warehouse, and now it is sitting on your yard waiting to be stripped — or the empty has been stripped but not returned to the depot. On the export side, the mirror applies: an exporter who picks up an empty and takes too long to gate in the laden box for shipment accrues detention. The carrier owns the container and wants it back in circulation; detention is the rent for keeping it out of rotation.
A single delay routinely trips both clocks. A slow customs release runs your demurrage at the port; by the time you finally collect the box, you have eaten into — or blown through — your detention free time before it even reaches the warehouse. Some carriers bill a combined 'demurrage & detention' or merged free-time pool, but the underlying logic of in-terminal versus out-of-terminal still drives where and how fast the charge accrues.
| Dimension | Demurrage | Detention |
|---|---|---|
| Where the box sits | Inside the terminal / port yard | Outside the terminal (your yard, depot, road) |
| Container state | Full (awaiting collection) | Full or empty (awaiting strip / return) |
| Who bills it | Terminal / carrier | Carrier (container owner) |
| Typical free time (default) | ~3–7 calendar days | ~3–5 calendar days |
| Clock starts | Discharge from vessel | Gate-out from terminal |
| Clock stops | Container gated out | Empty returned to nominated depot |
| Primary driver of delay | Customs, documents, delivery order | Warehouse turnaround, haulier, depot queue |
Demurrage and detention are not flat fees. They are tiered, and the tariff steps up the longer the box is held — a deliberate design to force equipment back into circulation. A representative structure runs something like: a first bracket of chargeable days at a base rate, a second bracket at a higher rate, and a third bracket higher again. Actual rates vary widely by carrier, port, and equipment type, so treat any single figure as indicative rather than a quote — reefer and special equipment cost considerably more than the standard dry boxes used for resin. The point is the shape of the curve, not a headline number: every day held costs more than the day before.
The escalation is where the damage compounds. Run the arithmetic on a multi-container FCL parcel — a typical mid-size resin booking — held two weeks across both clocks. Even at modest blended rates, the bill climbs into four or five figures fast, and it is pure leakage: no goods improved, no value added, margin simply transferred to the carrier. This is why demurrage and detention belong in your landed-cost model from the outset, not as a surprise on the carrier invoice. They sit alongside freight, insurance, and duty as a real, plannable line — see how the pieces assemble in our note on how polymer pricing works.
Demurrage and detention are not freight costs — they are the price of friction in your own paperwork and your own warehouse. Almost every dollar is preventable before the vessel berths.
The triggers for resin parcels are predictable, which is precisely what makes them manageable. The recurring offenders:
- Customs and compliance holds — incomplete or inconsistent import documentation, REACH/import declarations, or HS-code queries that stop the box in the yard while demurrage runs. Get classification and REACH/RoHS compliance settled before arrival, not at the gate.
- Delayed delivery orders (DO) — the carrier will not release the box until freight, documents, and any local charges are settled. A DO held up for a single afternoon can cost a full demurrage day across an entire parcel.
- Financing and original B/L delays — telex release not actioned, original bills of lading still in courier transit, or an LC document discrepancy freezing release. The bill of lading is the key that opens the box; if it is late, demurrage is automatic.
- Plant, warehouse, or yard congestion — no space to strip the resin, or no labour booked, so full boxes idle on your yard accruing detention.
- Chassis and haulier shortages — no truck, no chassis, no move; the box cannot leave the terminal even when it is cleared and paid.
- Peak-season and congestion pile-ups — gateway congestion stretches every step, and free time keeps running through it unless formally suspended.
Mitigation is overwhelmingly front-loaded. By the time a box is discharging, most of your options are gone. The highest-leverage moves, in rough order of impact:
| Lever | What to do | Why it works |
|---|---|---|
| Negotiate free time at booking | Commit volume; secure 14–21+ combined free days | Cheapest insurance you will ever buy — extends both clocks before any delay |
| Pre-clear customs | File entry and documents before vessel arrival; resolve HS-code and REACH queries early | Eliminates the single biggest demurrage trigger |
| Finance documents early | Action telex release / arrange originals and LC docs ahead of arrival | A released B/L means an immediately collectable box |
| Pre-book haulage & chassis | Lock trucking and chassis against the ETA, not the discharge | Avoids detention while a box waits for a move |
| Schedule warehouse capacity | Reserve labour and floor space against arrival window | Fast strip-and-return stops the detention clock dead |
| Choose the gateway deliberately | Weigh a quieter port against demurrage risk at a congested marquee port | Lower congestion can beat a cheaper-on-paper route |
| Monitor and dispute | Track gate timestamps and customs holds; file waivers promptly with evidence | Carrier-caused or force-majeure delays can be recoverable |
Two operational details pay for themselves. First, optimise the strip-and-return loop: the faster you unload resin bags or bulk and return the empty, the less detention you risk — efficient container loading and packaging on the export side makes destination handling faster too. Second, get the Incoterm right for who controls carriage at destination. Under CIF/CFR the seller books the main leg but destination demurrage and detention fall to you; under FOB you control carriage and own the risk from origin. Knowing exactly where your responsibility begins — and reading the booking, not just the three-letter term — is foundational; our Incoterms 2020 guide breaks down the cost-and-risk split.
Treat demurrage and detention the way you treat MFI tolerance or moisture spec — as a known, bounded variable to be engineered out, not a surprise to be absorbed. Negotiate the free time, clear the paperwork early, line up the haulier and the warehouse, and the charges that quietly drain so many resin imports simply never start. If you want the documentation, financing, and logistics sequenced so the box never idles, the OmniaStrata desk can structure the shipment end to end — talk to us.
Frequently asked
Questions on the desk
What is the difference between demurrage and detention?
Demurrage is charged by the carrier or terminal when a full container remains inside the port or terminal beyond the allotted free time, occupying yard space. Detention is charged when the container is taken outside the terminal — for unloading at your warehouse — and not returned (empty) within its free time, or when an exporter holds the box too long before gating in a full export load. In short: demurrage is the in-terminal clock, detention is the out-of-terminal clock. One late delivery order plus a slow warehouse turnaround can trigger both.
How much free time do I get on a container of polymer?
Carrier defaults commonly fall in the range of 3–7 calendar days for demurrage and 3–5 days for detention, but these are starting points, not fixed rules. Free time is set at booking and is negotiable against volume — regular resin importers frequently secure 14, 21, or even 28 combined free days. Always confirm whether free time is quoted in calendar or working days, and whether it counts from discharge or from gate-out.
Who pays demurrage and detention on a resin import?
It depends on the Incoterms 2020 rule and the contract of carriage. Under CIF or CFR the seller arranges main carriage, but demurrage and detention at destination almost always fall to the buyer once the goods discharge. Under FOB the buyer controls carriage and bears these charges from origin. The decisive factor is who holds the bill of lading and the carrier contract at destination — read your booking, not just your Incoterm. See our [Incoterms 2020 guide](/blog/incoterms-2020-for-polymer-buyers) for how cost and risk split.
Can demurrage and detention charges be waived or reduced?
Sometimes. Carriers may grant waivers for documented force majeure, terminal congestion, or carrier-caused delays such as a missed delivery order. File the dispute promptly with evidence — gate timestamps, customs hold notices, equipment-availability records. The stronger lever is prevention: pre-clear customs, finance the documents early, and book extended free time before the box ever moves.
Does port congestion change my free-time clock?
Not automatically. Free time generally keeps running during congestion unless the carrier issues a formal suspension or the terminal declares a recognised disruption. This is why importers into congested gateways negotiate longer free time as standard and monitor vessel and yard status closely. Picking a less-congested gateway can be cheaper than the demurrage premium at a marquee port — see our notes on [export and import gateways](/blog/global-polymer-export-ports).
General market commentary from the OmniaStrata desk, provided for information only. It is not legal, financial, tax, or trading advice, and it is not an offer or a commitment to any terms. Figures such as price ranges, spreads, financing costs, and credit periods are illustrative market context, not OmniaStrata's rates or terms. Actual contract terms — including price, payment instrument, credit, insurance, and Incoterms — are agreed in writing on a per-transaction basis and at OmniaStrata's discretion. Market conditions change; figures reflect the publication date.