The master comparison table
| Feature | Demurrage | Terminal Storage | Detention | Per Diem |
|---|---|---|---|---|
| Who bills | Shipping line | Transnet Port Terminals (TPT) via clearing agent | Shipping line | Shipping line (US/EU term = detention) |
| Where is the container | Inside the terminal — full, not yet collected | Inside the terminal — full, not yet collected | Outside the terminal — at your warehouse or depot | Outside the terminal — same as detention |
| What is being measured | Overstay of the carrier's equipment inside the terminal | Overstay in the terminal stack (ground space) | Extended use of the carrier's equipment outside the terminal | Same as detention — extended equipment use |
| Clock starts | After carrier free days expire (from discharge or availability date) | After TPT free days expire (3 calendar days from availability, effective 1 April 2025) | When the full container gates out of the terminal | When the full container gates out (same as detention) |
| Clock stops | When the container gates out of the terminal | When the container gates out of the terminal | When the empty container gates in at the carrier's nominated return depot | Same as detention — empty return at nominated depot |
| Free days | Negotiated with shipping line at booking (typically 5–14 days) | Fixed by TPT tariff — currently 3 calendar days at all TPT terminals | Negotiated with shipping line at booking (often combined with demurrage free days) | Negotiated — same as detention |
| Can run simultaneously with other charges? | Yes — with terminal storage | Yes — with demurrage | No — starts when demurrage/storage end | No — starts when demurrage/storage end |
| Dispute route | Carrier's local port agent — written dispute, reference B/L number | Clearing agent → TPT directly | Carrier's local port agent — reference booking number + empty return receipt | Carrier's local port agent — same as detention |
How the clocks work through a container's journey
It is easiest to understand the four charges in sequence. Follow a single 40ft container from vessel discharge at Durban to empty return — noting which clock is running at each stage.
| Day | Event | Demurrage clock | TPT storage clock | Detention clock |
|---|---|---|---|---|
| 1 | Vessel discharges; container stacked; availability declared | Free days begin (e.g. 7 free days) | Free days begin (3 calendar days) | Not started |
| 4 | TPT free period expires; demurrage still in free days | Still free | Day 1 of TPT storage charges | Not started |
| 8 | Carrier demurrage free days expire; TPT storage still running | Day 1 of carrier demurrage | Day 5 of TPT storage (both clocks running) | Not started |
| 11 | SARS release issued; truck collects; container gates out | Stops — 4 days charged | Stops — 8 days charged | Starts — detention free days begin |
| 13 | Container de-stuffed; detention free days (e.g. 5 days) still running | Stopped | Stopped | Day 3 of detention free days |
| 17 | Detention free days expire; empty not yet returned | Stopped | Stopped | Day 1 of detention charges |
| 19 | Empty returned to carrier's depot; gate-in recorded | Stopped | Stopped | Stops — 2 days charged |
Final tally for this example: 4 days carrier demurrage + 8 days TPT storage + 2 days detention = three separate invoices. Note that demurrage and TPT storage overlapped on Days 8–10, meaning you were paying two charges simultaneously.
Combined vs split free time — know your carrier's model
Some carriers offer combined free time — a single pool of days that covers both demurrage and detention. Under this model, if you have 14 combined free days, those days can be used either inside the terminal (avoiding demurrage) or outside (avoiding detention). Once the pool is exhausted, charges begin regardless of where the container is.
Other carriers run separate free-time pools — a fixed number of days for demurrage and a different number for detention, each with its own clock. Under this model, you cannot "save" unused demurrage free days and apply them to detention.
Always confirm your carrier's model at the time of booking. Ask specifically: "Are your free days combined or split?" This affects how you plan collection and empty return scheduling.
Per diem — is it the same as detention?
Yes, for practical purposes. "Per diem" literally means "per day" in Latin and is used by some shipping lines — particularly those headquartered in the United States — as their label for the daily charge on equipment used outside the terminal beyond free time. It is functionally identical to detention: it starts when the container leaves the terminal full, stops when the empty is returned, and is billed by the shipping line.
In the South African market, "detention" is the standard term and most carriers operating ZA trade lanes (Maersk, MSC, CMA CGM, Hapag-Lloyd, etc.) use it in their local tariffs. If you receive an invoice with a "per diem" line item, treat it as detention for accounting and dispute purposes.
One dashboard for all four clocks
Real-View SCM tracks your containers across demurrage, TPT storage and detention free-day windows simultaneously — so you always know which clock is most urgent.
Explore Real-View SCM →Frequently asked questions
Can demurrage and detention run at the same time?
No — not from the same carrier. Demurrage applies while the container is inside the terminal. Once it gates out, demurrage stops and detention begins. However, on separate containers you could have one container accruing demurrage (still inside the terminal) while another is accruing detention (returned empty not yet gated in). Always check each container individually.
Who is liable for demurrage and detention — importer or clearing agent?
The importer (consignee) is the ultimate liable party. The clearing agent acts as your agent and facilitates the process, but the contract with the carrier is between the carrier and the bill-of-lading holder. If your clearing agent caused a delay through negligence — for example, by failing to lodge documents you provided on time — you may have a recourse claim against them, but that is a separate contractual matter from your obligation to the carrier or TPT.
What is a "combined demurrage and detention invoice"?
Some carriers issue a single invoice that bundles demurrage and detention charges together, with a single free-day pool as described above. This is an administrative convenience — the charges themselves remain conceptually distinct (one for inside the terminal, one for outside). Review the line-item breakdown to ensure the dates and day counts are correct for each phase.
Is terminal storage (TPT) tax-deductible for the importer?
Yes, in principle, port and terminal charges including storage fees are typically deductible business expenses. They are also included in the cost of goods for customs valuation purposes under certain circumstances — consult your tax practitioner for guidance specific to your situation. The VAT component (15%) is reclaimable as an input tax credit if you are VAT-registered and hold a valid tax invoice.
Does the Incoterm (FOB, CIF, etc.) affect who pays demurrage?
The Incoterm determines who bears freight and risk up to a certain point in the journey. Once the goods are at the destination port and the bill of lading transfers to the consignee (importer), the demurrage obligation follows the container — and that is the importer's responsibility regardless of whether the Incoterm was FOB, CIF or any other. The only exception is if your contract of sale explicitly allocates destination demurrage to the seller — which is very unusual and must be stated clearly in writing.
Related guides
Sources: Transnet Port Terminals tariff schedule; Maersk advisory 28 February 2025; SARS customs tariff. This guide provides general information — verify current tariffs and billing conventions with your freight forwarder or clearing agent. Last updated June 2026.