Sea freight costs are made up of more than the headline rate per container. Quotes typically combine a base rate with a stack of surcharges and additional fees, and rates themselves move with route, fuel, demand, and disruption. For UK businesses budgeting shipments or comparing forwarders, that lack of visibility can make it hard to know whether a quote is competitive, which questions to ask, and when a contract beats spot.
This guide breaks down how sea freight costs are structured, what drives rate movements, and the main surcharges you will see on a quote, with UK-specific factors such as post-Brexit customs and port handling, plus practical guidance on reading a quote and choosing between spot and contract pricing.
Key takeaways
- A sea freight quote is built up of three layers: the base rate, surcharges, and additional fees such as customs, inland transport, and port charges.
- Rates move with route and lane, container type, FCL vs LCL volume, supply and demand, fuel costs, peak season, and disruption on key shipping corridors.
- Common surcharges include BAF, THC, GRI, PSS, War Risk Surcharge, CAF, Congestion Surcharge, and Low Sulphur Surcharge. Each should be itemised on quotes.
- UK importers should factor in post-Brexit customs friction, port handling at Felixstowe, Southampton, or London Gateway, and inland transport. Spot rates suit ad-hoc shipments; contract rates suit predictable volumes.
How are sea freight costs calculated?
Sea freight costs are calculated as the sum of three layers: a base ocean rate, a series of surcharges, and additional fees for activities outside the ocean leg. The base rate covers the move between origin and destination ports, surcharges absorb cost variables such as fuel and terminal handling, and additional fees cover customs, inland transport, storage, and similar services.
FCL pricing is quoted per container, typically per 20ft or 40ft unit, with high cube and reefer (refrigerated) containers attracting different rates. LCL pricing is quoted per cubic metre or per 1,000 kg, whichever is greater, on a weight-or-measure basis.
What factors affect sea freight costs?
Sea freight rates are driven by a combination of route and lane, container type and size, FCL or LCL volume, weight, supply and demand, fuel costs, peak season patterns, and disruption on key corridors. Most of these factors move independently, which is why sea freight pricing can shift sharply between quotes for the same lane only weeks apart.
Route and lane matter because some corridors carry more capacity and competition than others. Major east-west lanes such as Far East to North Europe see active rate competition between carriers, while smaller lanes carry premium for thinner service. Container type and size also affect cost: 40ft units offer lower per-cubic-metre cost than 20ft, and high cube, reefer, flat rack, and open top equipment are priced separately. FCL is priced per container regardless of how full it is, while LCL is priced per cubic metre or weight, with a crossover point at which a small FCL becomes cheaper than a large LCL.
Supply and demand drives the underlying market. The Drewry World Container Index and the Freightos Baltic Index are widely used market benchmarks for tracking spot rate movements on major lanes, and either can be referenced to sense-check whether a quoted rate is in line with the broader market. Fuel costs feed directly into surcharges through the Bunker Adjustment Factor, peak season patterns drive Peak Season Surcharges and General Rate Increases, and disruption on key corridors compounds all of this. Approximately 30% of global container trade transits the Suez Canal (J.P. Morgan Research), and around 11% of global trade and a third of seaborne oil pass through the Strait of Hormuz (UNCTAD), so any sustained pressure on those routes feeds through into rates and surcharges across the wider market.
What are the main sea freight surcharges?
Sea freight surcharges are additional charges added to the base ocean rate to cover specific cost variables such as fuel, terminal handling, or insurance risk. Carriers and forwarders generally itemise surcharges on quotes, and a clean breakdown is the easiest way to understand what you are paying for and why. The table below sets out the main surcharges UK businesses will see on quotes and invoices.
| Surcharge | Stands for | What it covers |
| BAF | Bunker Adjustment Factor | Adjusts the base rate to reflect changes in bunker fuel prices. Reviewed periodically as fuel costs move and is one of the largest variable surcharges on a quote. |
| THC | Terminal Handling Charge | Covers the cost of handling containers at the origin and destination ports, including loading, unloading, and movement within the terminal. Charged at both ends of the journey. |
| GRI | General Rate Increase | A carrier-led increase to base rates on a specific lane, typically announced in advance and applied when demand rises or capacity tightens. Most common on major east-west lanes. |
| PSS | Peak Season Surcharge | Applied during peak demand periods, typically late summer through autumn for Far East to Europe trade, to reflect higher demand and reduced effective capacity. |
| WRS | War Risk Surcharge | Applied when vessels transit areas designated as elevated risk by maritime insurers, covering the additional cost of war risk insurance premiums for the carrier. |
| CAF | Currency Adjustment Factor | Adjusts for currency movements between the carrier billing currency and the trade lane currency. Less common than it once was, but still seen on certain routes and contracts. |
| Congestion Surcharge | Port Congestion Surcharge | Applied when specific ports experience sustained congestion, covering the additional vessel time and operational cost involved in calling at affected terminals. |
| Low Sulphur Surcharge | Low Sulphur / IMO 2020 Surcharge | Reflects the additional cost of compliant low sulphur marine fuel under IMO regulations limiting sulphur content in vessel emissions. |
UK-specific cost factors UK businesses should plan for
UK importers and exporters carry several cost factors above and beyond the global rate picture. Post-Brexit customs requirements, port handling at major UK gateways, VAT and duty on imports, and inland transport from port to inland destination all feed into the true landed cost of a sea freight shipment, and missing them in the budgeting stage is a common cause of margin surprise later.
Post-Brexit customs friction now applies to EU as well as non-EU trade. Each shipment requires a full UK customs entry, with commodity codes, declared values, and Incoterms supporting the calculation of import duty and VAT. Errors lead to delays, demurrage, and in some cases re-examination, all of which carry cost, so working with a freight forwarder with integrated customs capability is now the practical default for most UK businesses.
UK port handling adds a layer of cost specific to the gateway used. The Port of Felixstowe handles around 36% of all containers arriving and departing from the UK (Statista), with Southampton and London Gateway making up most of the remaining deep-sea container traffic, and THC and port-specific service fees vary between gateways. Inland transport from port to final destination is the third UK-specific factor, with road haulage costs, congestion around major ports, and rail capacity all feeding into the door-to-door price. Around 95% of UK imports and exports move by sea (Statista, UK Department for Transport), and very few of those shipments end at the port gate, so inland cost is typically the next-largest line item after the ocean rate itself.
How to read a sea freight quote and what to ask your forwarder
A well-structured sea freight quote should clearly itemise the base rate, every surcharge, and every additional fee with a defined value, currency, and validity period. If a quote bundles charges into a single number, it is harder to evaluate and easier to underestimate. A short checklist when reviewing any sea freight quote:
- Is the base rate quoted per container (FCL) or per cubic metre / 1,000 kg, whichever is greater (LCL)?
- Are all expected surcharges itemised, including BAF, THC at both ends, and any lane-specific charges such as WRS or PSS?
- What is the rate validity period, and what triggers a re-quote?
- Are customs clearance, port handling, and inland transport included, or quoted separately?
- What free time applies before demurrage and detention charges begin, and what are the daily rates after that?
- Which Incoterms are assumed, and which costs sit with the seller versus the buyer?
Incoterms reward attention. EXW puts almost all responsibility and cost on the buyer, while DDP puts almost all on the seller. Most UK importers operate somewhere between, often FOB or CIF, and small differences in Incoterm choice can shift several percentage points of cost between parties. The ICC Incoterms reference is the authoritative source if any term is unclear.
Should you book sea freight on spot rates or contract?
Spot rates are negotiated per shipment and reflect the live market, which suits ad-hoc bookings and businesses with unpredictable volumes. Contract rates are negotiated for an agreed volume over a fixed period, typically 3, 6, or 12 months, and suit predictable volumes and rising-rate markets. Many UK businesses use a combination, contracting their core volume and topping up on spot when needed.
The decision turns on volume predictability, market direction, and risk appetite. If sea freight pricing on your main lanes is rising and capacity is tight, contracts protect against further rate spikes and improve forecasting. If the market is soft, spot rates often beat contract levels, at the cost of weaker security on space. UniOcean publishes 3, 6, and 12 month spot contract options on its sea freight service page, which is one of the cleaner ways to lock in pricing for a defined period without committing to long-term volume guarantees.
Frequently asked questions
Are FCL or LCL rates cheaper?
LCL is cheaper for small shipments because you only pay for the volume or weight you ship. FCL becomes cheaper once your volume reaches the point where booking a full container costs less than the cumulative LCL charge. The crossover point varies by lane and rate, and most forwarders will run both quotes if asked. For regular full-container volumes, FCL is almost always the better choice. See more information here.
How does fuel price affect sea freight cost?
Fuel cost is built into sea freight rates through the Bunker Adjustment Factor (BAF), which moves with bunker fuel prices. When oil prices rise, BAF increases and feeds through to overall rates. The Low Sulphur Surcharge also reflects fuel cost, specifically the higher cost of compliant fuel under IMO regulations. Fuel is one of the larger variable inputs to the price you pay.
Why do sea freight rates change?
Sea freight rates change because the underlying market is sensitive to supply and demand on each lane, fuel cost movements, peak season patterns, and disruption on major shipping corridors. Carrier alliance restructuring and port congestion add to that picture. Tracking indices such as the Drewry World Container Index and Freightos Baltic Index gives a sense of where headline rates are moving on major lanes.
How does disruption affect sea freight cost?
Disruption affects sea freight cost in several ways: longer routings raise base rates and fuel cost; war risk and congestion surcharges may apply where appropriate; capacity tightens as vessels spend more time at sea; and demurrage exposure increases as schedules slip. The combined effect during sustained disruption is typically a rise in headline rates and a higher proportion of cost in surcharges.
Reading your next quote with confidence
Sea freight pricing rewards transparency. Once you can see a quote as a base rate plus a defined set of surcharges plus a small number of additional fees, the picture stops feeling opaque and starts feeling like a normal commercial conversation. The market itself remains volatile, driven by supply and demand, fuel, peak season, and disruption, but the structure of a quote is stable enough to compare cleanly between forwarders. For UK businesses, the post-Brexit customs layer, the choice of UK port, and a clear-eyed view of when contract pricing earns its place over spot are the most useful additions. A forwarder who itemises all of this up front is doing you a favour, even if the headline rate looks higher than a vaguer alternative.
Get a sea freight quote from Uniserve
Uniserve is the UK leading independent logistics and global trade management provider, part of GB Global. UniOcean is our end-to-end sea freight service, covering FCL and LCL through major UK ports including Felixstowe, Southampton, and London Gateway, with itemised quotes and 3, 6, and 12 month spot contract options for businesses that want predictable pricing. If you would like a quote on a specific shipment, or a conversation about contract options for your regular volumes, visit our UniOcean sea freight page or get in touch directly to start a tailored discussion.