Master Air Waybill (MAWB)

A master air waybill (MAWB) is the air waybill an airline issues for a shipment it accepts from a freight forwarder or consolidator. When the forwarder groups several shippers' cargo into one consolidation, the MAWB covers the consolidation as a whole: it names the forwarder, or its origin office, as shipper and its destination office or agent as consignee, and shows the total pieces and weight. Each shipper gets its own house air waybill (HAWB) from the forwarder. For what an air waybill is, and why it is not a document of title, see air waybill (AWB).

MAWB vs HAWB

• Issued by: the MAWB is the airline's document, though the forwarder usually completes it as the airline's agent; the HAWB is the forwarder's own document
• Parties shown: the MAWB shows the forwarder and its destination agent; the HAWB shows the actual shipper and consignee
• How many: one MAWB per consolidation; one HAWB per shipper, so several house air waybills sit under one master
• Tracking: the airline tracks the MAWB number; the forwarder tracks the HAWB

The MAWB number

A MAWB number has 11 digits: a 3-digit airline prefix assigned by IATA, then an 8-digit serial number, usually written with a hyphen, such as 123-12345675. The last digit of the serial is a check digit: the remainder when the first seven digits are divided by 7 (1234567 ÷ 7 leaves 5, hence 12345675). A number whose check digit does not match has been mistyped, so the check catches many keying errors before a booking or a customs filing goes out. The prefix tells you which airline to track the master with.

How the MAWB fits consolidation

Consolidation is why masters and houses exist. Airlines rate air cargo per kilo of chargeable weight, with lower rates at higher weight breaks, so a forwarder that tenders many shippers' cargo as one consignment under one MAWB is rated on the combined weight rather than each shipper's small one. At destination the forwarder's agent collects the consolidation from the airline against the MAWB, breaks it down (deconsolidation) and releases each house shipment against its HAWB. A shipment large enough to travel alone, or one booked directly with the airline, can move on its own MAWB with no house air waybill beneath it.

What CBP requires

For flights to the United States, the advance electronic cargo data filed with CBP carries the master air waybill number and, for a consolidation, the house air waybill numbers and data under it (19 CFR 122.48a). Air Cargo Advance Screening (ACAS) data is filed at the lowest air waybill level, which is the house air waybill where there is one (19 CFR 122.48b).

Common mistakes

• Giving the consignee only the MAWB number for a consolidated shipment: the airline releases the master to the forwarder's agent, so the consignee and its customs broker need the house number
• Tracking a house shipment on the airline's website with the HAWB number, which the airline does not hold
• House air waybills whose pieces and weights do not add up to the totals on the master

For exports from the US, Airlift operates as a TSA-regulated Indirect Air Carrier and issues its own house air waybills under the airline's master on air freight shipments. The ocean equivalent of the MAWB is the master bill of lading. Size a shipment first with the chargeable weight calculator.