To calculate the Modulo 11 check digit, use the following process:
- Assign a weight to each character in the code, starting with a weight of 2 in the right-most position and incrementing by one as you move to the left. After you reach a weight of 7, the next digit will have a weight of 2 (that is, weighting goes from 2 to 7 and then wraps around back to 2)
- Multiply the value of each character by its weight, and sum the result of all the characters
- Perform a modulo 11 on the result (sum) of step 2
Assume an example of an account number "1234567" that will have a mode 11 check digit added, making it of the form “1234567X”:
Table 2.4. Mode 11 Check Digit Example
| Example | 1 | 2 | 3 | 4 | 5 | 6 | 7 | Mode 11 Check digit |
|---|---|---|---|---|---|---|---|---|
| (1) Add weight | 2 | 7 | 6 | 5 | 4 | 3 | 2 | X |
| (2) digit × weight | 2 | 14 | 18 | 20 | 20 | 18 | 14 | |
| (3)add all, get sum | Sum=2+14+18+20+20+18+14=106, 106 Mod 11 = 4 | X = 4 | ||||||
| (4)Result | 12345674 | |||||||
And for the mode 1110, take “1234567”as example, just to use the mode 11 for “1234567”to calculate the first mode 11 check digit, is 4, then do mode 10 for “12345674”then calculate out the second mode 10 check digit, is 1, so the whole result is “123456741”
![[Tip]](http://www.crifan.com/files/res/docbook/images/tip.png) | Tip |
|---|---|
While most MSI barcodes include at least one checksum digit, so in many case, the printed MSI barcode does not show out the first checksum digit, while only show the second checksum digit if exists. |
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| 2.4.1.1. Mode 10 and Mode 1010 |  | 2.5. Usage Filed |
