A very simple check digit method would be to take the sum of all digits (digital sum) modulo 10.
This would catch any single-digit error, as such an error would always change the sum, but does not catch any transposition errors (switching two digits) as re-ordering does not change the sum.
Banks in the USA use SWIFT codes, but they don't use IBANs.
A BSB Number is a unique number which identifies both the Financial Institution and the point of representation of a particular account in Australia. You can search for a BSB and its details or download the entire BSB directory by clicking on the "BSB Search" button below.
Its check digit is generated the same way as the UPC except that the even digits are multiplied by 3 instead of the odd digits.
EAN (European Article Number) check digits (administered by GS1) are calculated by summing each of the odd position numbers multiplied by 3 and then by adding the sum of the even position numbers.
For example, take the ISBN 0-201-53082-1: The sum of products is 0×10 2×9 0×8 1×7 5×6 3×5 0×4 8×3 2×2 1×1 = 99 ≡ 0 (mod 11). Note that positions can also be counted from left, in which case the check digit is multiplied by 10, to check validity: 0×1 2×2 0×3 1×4 5×5 3×6 0×7 8×8 2×9 1×10 = 143 ≡ 0 (mod 11).
Systems with weights of 1, 3, 7, or 9, with the weights on neighboring numbers being different, are widely used: for example, 31 31 weights in UPC codes, 13 13 weights in EAN numbers (GS1 algorithm), and the 371 371 371 weights used in United States bank routing transit numbers.To reduce this failure rate, it is necessary to use more than one check digit (for example, the modulo 97 check referred to below, which uses two check digits - for the algorithm, see International Bank Account Number) and/or to use a wider range of characters in the check digit, for example letters plus numbers.The final digit of a Universal Product Code is a check digit computed as follows: The final character of a ten-digit International Standard Book Number is a check digit computed so that multiplying each digit by its position in the number (counting from the right) and taking the sum of these products modulo 11 is 0.BSB data is updated during the first week of each month. Alternatively you can purchase the BSB Numbers in Australia Book and CD.This quarterly publication can be ordered direct from Blue Star Print Australia by completing the order form below.