**Air Way Bill Check Digit Calculator** This page explains the algorithm for calculating the last digit (check digit) of a MAWB.

Method of calculating the check digit

The MAWB number consists of a total 11 digits. These 11 digits can be divided into 3 parts

**1] The first 3 digits are the Airline Prefix which are unique for every airline **

**2] The next 7 digits is the Serial Number of the AWB **

**3] The last digit is the Check digit **

For example the AWB number is 589 8114074 3

Disregard the first 3 unique Airline Prefix numbers and the last Check Digit [because that’s what we are going to find and match it with the actual check digit]

**Just consider the 7 digit Serial Number, 8114074 and divide this by 7 [the number 7 is a constant, Mod7] **

The remainder determines the Check Digit

*Example, Serial Number 8114074 when divided manually by 7 the remainder is 3. This remainder matches with the check digit of the AWB, hence the AWB number 589 8114074 3 is correct *

*Note Since we are dividing the Serial Number by the constant number 7, the remainder will always be a number less than 7, i.e a number between 0 to 6.

For example If the remainder is 7, again it can be divided by 7 and the remainder will be 0

If the remainder is 8, again it can be divided by 7 and the remainder will be 1

If the remainder is 9, again it can be divided by 7 and the remainder will be 2

Hence, as a thumb rule, the check digit of an AWB number will always be a number less than 7. The moment you come across the last number as 7, 8 or 9 instantly you can say that the AWB number is not valid.