Here is a code snippet to help you validate the Australian Tax File Numbers also known as TFN.
The TFNs are 9 character long Numeric values
Here is a Sample TFN 123456782 which you can use to do your testing.
Function Validate_TFN(ByVal value As String) As Boolean
‘ best-answer.net
Dim bok As Boolean = False
‘ the following algorithm is used to calculate the validity of TFN
‘ 9 characters
Dim myTFN As Char()
‘
Dim checksum As Double
Dim count As Integer
myTFN = value.ToCharArray()
Dim i As Integer
For i = 0 To 8
Select Case i
Case 0
checksum += myTFN(0).ToString * 1
Case 1
checksum += myTFN(1).ToString * 4
Case 2
checksum += myTFN(2).ToString * 3
Case 3
checksum += myTFN(3).ToString * 7
Case 4
checksum += myTFN(4).ToString * 5
Case 5
checksum += myTFN(5).ToString * 8
Case 6
checksum += myTFN(6).ToString * 6
Case 7
checksum += myTFN(7).ToString * 9
Case 8
checksum += myTFN(8).ToString * 10
End Select
Next
checksum = checksum / 11
bok = (Math.Floor(checksum) = Math.Ceiling(checksum))
Return bok
End Function