Diagnosis
The company number must be checked when it is entered. The check provedthat the number is incorrect.
The following checks must be made:

• The first three digits must be 010 to 099 or greater than 110.


• The last digit of the company number is the check digit. Both the check
digit calculated and the last digit from the total of check digits andthe constant 5 can be used.
The check digit is calculated in the following way:

• The company number digits (digits 1 to 7) are, starting with the first
digit, multiplied with the factors 1, 2, 1, 2, 1, 2, 1.

• The sum of the digits is calculated from the individual products.


• The sums of the digits are added together.


• The total is divided by 10.


• The remaining amount is the check digit.