A Block Space Agreement (BSA) is a contract between a freight forwarder and an airline. It secures a fixed amount of air cargo space on specific flights or routes for an agreed period.
You may also see the term written as Blocked Space Agreement. Both terms refer to the same general air freight arrangement.
Instead of requesting cargo space for each shipment, the forwarder secures capacity in advance. It can then use this space for suitable customer shipments.
This can provide more consistent access to air cargo space, especially on busy trade lanes and during periods of high demand.
A BSA sets the commercial and operational terms between the airline and freight forwarder. These may include:
- Route or fligh
- Allocated weight or ULD space
- Flight frequency
- Agreement period
- Pricing and other commercial terms
The forwarder commits to the agreed capacity and may still have to pay for unused space, depending on the contract terms.
In return, the airline provides the agreed capacity under the BSA terms. This gives the forwarder more consistent access to space for regular customer shipments.
The main difference is when and how the freight forwarder secures airline capacity.
| BSA Air Freight | Spot Air Freight | |
|---|---|---|
| Capacity | Reserved in advance | Booked shipment by shipment |
| Pricing | Based on agreed BSA terms | Based on current market rates |
| Commitment | Forwarder commits to agreed capacity | No long-term capacity commitment |
| Peak Season | Access to pre-arranged capacity | Space may become limited |
| Best For | Regular or predictable shipments | Occasional or irregular shipments |
BSA capacity does not suit every shipment. The forwarder should consider the route, cargo, schedule, available capacity, and current market conditions when choosing between BSA and spot air freight.
BSA capacity can help freight forwarders manage regular air cargo volumes more effectively.
More Consistent Space Access
The forwarder has a defined allocation instead of relying entirely on available spot-market capacity. This can become particularly useful during peak seasons or periods of strong air cargo demand.
More Predictable Planning
Regular capacity makes it easier to plan recurring shipments around specific routes and flight schedules. This can benefit shippers with consistent or high-volume air freight requirements.
Agreed Commercial Terms
BSA arrangements usually establish commercial terms in advance. This can reduce some exposure to short-term spot-market changes.
A BSA secures an agreed capacity allocation between the freight forwarder and airline. But it should not be treated as an unconditional guarantee that every shipment will fly exactly as planned.
The cargo must still meet the airline’s acceptance, documentation, packaging, weight, dimension, and regulatory requirements.
Flight cancellations, operational changes, capacity restrictions, and other disruptions can also affect uplift.
The practical advantage of a BSA is pre-arranged access to capacity on the agreed route. This reduces the forwarder’s dependence on last-minute spot availability.
BSA capacity can be useful for shippers with:
- Regular air freight volumes
- Recurring shipments on the same trade lane
- Peak-season capacity requirements
- Time-sensitive cargo
- High-volume e-commerce or commercial shipments
For occasional shipments, spot air freight may still provide enough flexibility.
The right option depends on the route, cargo, shipment frequency, volume, schedule, and current air freight market.
1. Who signs a BSA?
A Block Space Agreement typically involves an airline and a freight forwarder or other cargo capacity buyer. The freight forwarder can then use the allocated capacity for suitable customer shipments.
2. How long does a BSA last?
The duration depends on the agreement. A BSA may cover a particular season, several months, or a longer period. The agreement sets the capacity, routes, schedules, and commercial terms.
3. Is BSA air freight cheaper than spot air freight?
BSA rates follow the agreed commercial terms, while spot rates respond more directly to current market conditions. The actual cost depends on the route, cargo, capacity, season, and surcharges.
The main advantage of a BSA is more consistent access to pre-arranged capacity, not necessarily the lowest rate.
ASLG uses BSA capacity as part of its wider air freight services from China. For available BSA routes, capacity options, and shipment requirements, see our BSA air freight service.
