How to calculate demurrage in the DRC? Practical guide 2026

In the Democratic Republic of the Congo, the total cost of a container immobilized after its free time is never one single line. Between the carrier, the port, OGEFREM and OCC, several invoices stack up — often in different currencies, on different tariff structures, with starting points that don't align. For a freight forwarder or customs broker, knowing how to read and calculate these fees is the foundation of the trade. The client must receive an invoice that holds up; you must collect what is owed, without leaving hundreds of dollars sleeping in oversights or data-entry errors.

1. Distinguish the three cost families

Before any calculation, clarify what each word covers. Confusion between demurrage, detention and storage fees is the leading source of invoicing errors in the DRC.

Demurrage

Penalty charged by the carrier (Maersk, MSC, CMA CGM, Hapag-Lloyd…) when its container remains in the port area after the free time granted. The clock starts at container release date (or vessel discharge date depending on contract) and stops when the container exits the port with the cargo.

Detention

Penalty charged by the carrier when its container, having exited the port with cargo, is not returned within the contractual term. The clock starts at port exit and stops at the empty container's return to the carrier or its agreed depot.

Storage fees

Charged by the port authority or terminal operator (DGDA, OGEFREM, terminal operator) for occupation of port spaces. They add to carrier demurrage and follow a separate tariff.

👉 The same container 10 days late can simultaneously trigger three invoices: carrier demurrage, port storage fees, and — if exit drags further — carrier detention after exit. The total calculation must consolidate the three lines.

2. Free time — the calculation starting point

Free time is the number of days during which the carrier applies no penalty. It is contractually negotiated and varies by several factors:

The framework contract between the client and the carrier (annual volume, commercial tenure)
The arrival port (Matadi, Boma, Pointe-Noire transit, etc.)
The container type (20' dry, 40' dry, reefer, flat-rack, open-top)
The trade direction (import vs. export)
The season (high vs. low season on certain lines)

In the DRC, on the port of Matadi, typical import free time for a dry container commonly sits between 7 and 14 calendar days from vessel discharge. A high-volume client may have negotiated 21 days; an occasional one may end up at 5 days. Never assume free time: open the contract or the booking.

3. Carrier tariff — generally progressive

Once free time is exhausted, carriers nearly systematically apply a progressive tariff. The logic is to penalize increasingly as the container sits idle. A typical grid in West and Central Africa looks like:

Days 1 to 5 after free time: low tier (e.g., 50 USD/day for a 20' dry)
Days 6 to 10: medium tier (e.g., 100 USD/day)
Days 11 and beyond: high tier (e.g., 150 to 200 USD/day)

Exact numbers vary per carrier, contract and season — these are orders of magnitude, not official tariffs to be published. Always verify the active grid at the calculation date. A 40' container generally costs 1.5× to 2× the 20' tariff. A reefer (refrigerated) can cost 3× to 5× the dry tariff, due to electrical consumption and sensitive cargo.

4. Worked example: 20' dry container at Matadi

Take a 20' dry container arriving in Matadi on April 1, exiting the port with cargo on April 22. Contractual free time: 14 days. Progressive carrier tariff:

Free time: April 1 to 14 (14 days, free)
Days 15 to 19 (5 days, low tier at 50 USD) = 250 USD
Days 20 to 22 (3 days, medium tier at 100 USD) = 300 USD

Total carrier demurrage: 550 USD.

Add — typically — port storage fees for the same period, calculated on their own grid (often a fixed amount per day per container category). And depending on the freight contract, OGEFREM fees (DRC import freight coverage) which are not strictly demurrage but appear on the final client invoice.

5. The DRC-specific regulatory charges that add up

Beyond the carrier tariff, several DRC-specific lines typically complete an import-export invoice:

OGEFREM

The Office of Multimodal Freight Management charges import freight coverage. Calculation is generally a percentage of freight value. It is not demurrage, but appears on the final client invoice.

OCC

The Congolese Office of Control may charge inspection, scanning or certification fees depending on cargo nature.

DGDA

Beyond customs duties and taxes (which are not demurrage), the DGDA may apply correction penalties if declarations exit regulatory deadlines (see our guide on DGDA mistakes).

6. The 4 most common calculation mistakes

Confusing vessel arrival date with container release date. Free time generally starts at discharge, which can be one or two days after vessel arrival at quay.
Forgetting public holidays. In the DRC, carrier tariffs are in calendar days (so weekends and holidays count), but some contracts negotiate business days. Check line by line.
Applying a tier on the wrong slice. If a container accumulates 8 days past free time, that's not 8 days at tier 1 rate: it's 5 days at tier 1 + 3 days at tier 2.
Not re-checking the contract at each invoicing. Tariffs are regularly re-evaluated (often January 1 and July 1). A calculation done on an outdated grid can either undercharge the client or create a dispute.

7. Why automate this calculation

Calculating demurrage manually for one container, in an Excel sheet, is feasible. Doing it for 50, 200 or 500 containers per month, with multiple carriers, multiple container types, changing tariffs and different client contracts, becomes a structural source of errors and financial losses.

The main losses observed at forwarders moving to a dedicated tool:

Forgotten demurrage (not billed to end client): 5% to 15% of potential revenue
Tier errors (under-billing): 3% to 8%
Demurrage detected too late to react with the carrier (negotiation, waiver): variable

Surestaria automates the four steps: overflow detection (alert before the penalty hits), progressive calculation per the exact contract tariff, debit note or invoice automatically generated to the client, dashboard to pilot at-risk containers. You keep editorial control; the software does the repetitive work.

The right reflex: before panicking on a container that overruns, first verify the freight contract and the active grid. With a tool that hosts tariffs and triggers alerts, you act upstream — not in crisis mode.