AWB check digit calculator

Every air waybill number has 11 digits: a 3-digit airline prefix and an 8-digit serial. The prefix identifies the airline that issued the number, for example 020 for Lufthansa Cargo, 176 for Emirates or 180 for Korean Air. The last digit of the serial is the check digit.

To work it out, take the first 7 digits of the serial and divide them by 7. The remainder is the check digit. The prefix is not part of the calculation.

A remainder of 0 gives a check digit of 0. For example, 1234562 divides by 7 exactly, so the full number is 020-12345620. The check digit can never be 7, 8 or 9.

What the check digit catches, and what it misses

It catches many typing mistakes before the number reaches an airline. Swap the last two serial digits of the example and keep the old check digit (020-12345765), and the check fails, because 1234576 needs check digit 0.

It does not catch everything. A mistake that changes the 7-digit number by a multiple of 7 slips through: 020-12345605 also passes, because 1234560 also leaves remainder 5. A valid check digit only shows that the number is well-formed. It does not show that the airline allocated that number to you.

Where AWB Studio uses it

Enter a prefix and the first 7 serial digits to get the check digit and the full number. To check a number you already have, enter its first 7 serial digits and compare the result with its last digit. In the AWB Studio editor, the same calculation completes the number as you type, and the FWB validator will reject a message whose AWB number fails it when it opens at public launch.

More on air waybill numbers in the guides: fixing an invalid check digit and neutral AWB forms.