It is issued in a standard form under IATA Resolution 600a, which is why an air waybill from one carrier looks like an air waybill from another, and why the number has the same shape everywhere: eleven digits, made of a three digit airline prefix, a seven digit serial and one check digit computed as the serial modulo seven.
Air freight · the air waybill
The air waybill
The document every air shipment hangs off, what its number means, and the two things about it that surprise people who come from sea freight.
- Number length
- 11 digits
- Check digit
- serial mod 7
- Negotiable
- No
- Cargo liability
- 22 SDR/kg
What this desk is. OnBoard Courier places on board couriers: a vetted person carries the consignment in the cabin on a scheduled passenger flight and hands it over against a signature. The desk does not operate air freight, does not hold an airline contract and is not a forwarder. Air freight enquiries sent through this site are passed to a vetted forwarding partner, and the pages here are written so that you can tell which of the two you actually need.
What it is
The air waybill is the document of carriage for an air shipment. It records who is shipping, who is receiving, what is in the consignment, how much it weighs, how it is routed, what has been paid and on what terms, and it is the reference number everything else in the movement hangs off.
It is not a document of title. It is not negotiable. It does not control release of the goods against payment. If you have come from sea freight and are used to an original bill of lading doing work in a letter of credit, that work does not happen here and the mismatch has stranded a great many shipments.
Master and house
Most general air freight moves consolidated, and consolidation produces two layers of paper. The consolidator issues a house air waybill to each shipper in the group. The airline issues one master air waybill to the consolidator for the whole unit. Your shipment exists in both, and the two numbers behave differently.
The master moves when the aircraft moves, so it is the number that tells you whether the unit departed and landed. The house is the number that tells you what happened to your part of it after the unit was broken down, which is usually where the time goes. Asking a forwarder for the master when you want the house, or the other way round, produces a confident answer to the wrong question.
A direct shipment has only a master. That is one of the quiet advantages of buying direct rather than consolidated, and it is described alongside the cost difference on the comparison page.
Liability, and why it is smaller than people expect
Carriage by air between states that are party to it is governed by the Montreal Convention 1999. For cargo, the carrier's liability for destruction, loss, damage or delay is limited to 22 Special Drawing Rights per kilogram. The Special Drawing Right is an International Monetary Fund unit, so the figure in your currency moves with the exchange rate.
Two things follow. The limit is by weight, so a light and valuable consignment is protected least: a 3 kg box of semiconductor parts is covered for 66 SDR whatever is inside it. And the limit can be lifted only by declaring a higher value on the air waybill and paying a valuation charge at the time of shipping. It cannot be fixed afterwards.
This is a reason people move some consignments by hand rather than as freight, and it is worth being exact about why. A hand carry does not raise the airline's liability. What it does is keep the item in one identified person's custody for the whole movement, which removes most of the events a claim would arise from. The insurance question is still a separate question and should be answered before the movement, not after.
What has to be right before it flies
The description of goods has to be specific enough for screening and for customs. The consignee has to be a real receiving entity with a real address, not a branch name. The harmonised code, the country of origin and the value have to agree with the commercial invoice. Any special handling, dangerous goods declaration or temperature requirement has to be on the paperwork before the shipment is tendered, not mentioned on the phone.
Almost every air freight delay that is blamed on customs starts as a document that was filled in at the last minute by somebody guessing. The customs and Incoterms page covers the part of this that decides who is responsible for the guess.
Questions people actually ask
01What do the eleven digits mean?
Three digits of airline prefix, seven digits of serial number, and one check digit. The check digit is the seven digit serial divided by seven, taking the remainder. That is why a mistyped air waybill number usually fails validation immediately rather than pointing at somebody else's shipment.
02Is an air waybill a document of title?
No, and this is the difference that catches people who come from sea freight. A bill of lading can be negotiable, and possession of the original can control release of the goods. An air waybill is not negotiable. It is evidence of the contract of carriage and a receipt, and the goods are released to the consignee named on it. If you need payment secured against release, air freight is not the instrument and your bank needs to know that before the shipment moves.
03Master or house, which one do I get?
If you booked through a forwarder or consolidator you get a house air waybill from them. The master is between the forwarder and the airline and covers the whole unit, possibly with many houses inside it. Tracking the master tells you where the unit is. Tracking the house tells you where your shipment is once the unit is broken down.
04What is the carrier liable for?
Under the Montreal Convention 1999 the carrier's liability for cargo is limited to 22 Special Drawing Rights per kilogram, unless a higher value is declared on the air waybill and a valuation charge is paid. It is per kilogram of the affected package, not per shipment and not per invoice value. For most electronics, samples and spares that limit is far below the value of the goods, which is why cargo insurance is a separate decision and not an upsell.
05Who is responsible for what is written on it?
The shipper. The air waybill carries the shipper's declaration of the contents, and a description that does not match what is in the box is the shipper's problem at every subsequent step: screening, customs and, if something goes wrong, the claim. "Spare parts" is not a description. The commodity, the material and the harmonised code are.
Where this came from
- Scheduled network, airlines and frequencies: AeroDataBox scheduled route statistics as held by this site, retrieved 2026-09-07. It is a snapshot rather than a live timetable, it includes some all cargo operators but is not a complete freighter schedule, and a carrier that is not listed may still fly the pair.
- Distances: Great circle, computed from published airport coordinates. They are shorter than a flown track and are not routing distances.
- Block times: Modelled, not measured: great circle distance times a track factor of 1.06, divided by a cruise speed of 720, 830 or 880 km/h by distance band, plus thirty minutes of taxi across the two ends. This is the same model the route calculator on this site uses. A real timetable will differ.
- Industrial sites: Public company information, checked 2026-09-07. Nothing here states or implies that any company named is a customer of OnBoard Courier or of any operator.
- Air cargo rules and definitions: The ICAO Technical Instructions and the IATA Dangerous Goods Regulations for dangerous goods, IATA Resolution 600a for the air waybill, the Montreal Convention 1999 for carrier liability, and Incoterms 2020. Where this site holds no figure of its own it says so rather than inventing one.
Who publishes this. OnBoard Courier is a hand carry placement desk in Dubai. It does not fly air freight. These pages exist because the desk is asked to rescue air freight that has run out of time often enough to have learned where the line between the two sits, and because a comparison written by somebody who sells only one of the two options is not a comparison. Found an error? Tell us and we will correct it.
Air freight, the comparison · Corridors · The Atlas · Route calculator