Diagnosis
The check digit entered is inconsistent with the tax number. Verify thecheck-digit against the tax number as explained below.

Procedure
The check-digit is derived using modulus 11 on the sum of values pickedfrom a specific matrix.
Example: SG-3612295-05 (0). The check digit is derived by takingthe sum of the values from the following matrix.
Column starting from 0 to 9
Row Stating from 1 to 7
0 3 6 9 1 4 7 10 2 5
0 4 8 1 5 9 2 6 10 3
0 5 10 4 9 3 8 2 7 1
0 6 1 7 2 8 3 9 4 10
0 7 3 10 6 2 9 5 1 8
0 8 5 2 10 7 4 1 9 6
0 9 7 5 3 1 10 8 6 4
The row value is denoted by the order of the 7 digits after the prefix.The column value is given by the value of the digit in the 7-digit set.In the above example, the first digit 3 in the 7-digit number gives thevalue in row 1 column 3(ie 9), second digit 6 gives value in row 2coulmn 6 (=2), third digit 1 gives value in row 3 column 1 (=5), and soon.
The sum of the value = 9 + 2 + 5 + 1 + 3 + 6 + 1 = 27, gives aremainder of 5 when divided by 11 (ie the value of 27 under operationsof modulus 11). Therefore, the check digit for 3612295 is 05.