Here is a simple function


Function ccCheck(rng) As Boolean
Dim i As Long
Dim tmp

With rng
For i = 1 To Len(.Value) - 1
tmp = tmp + Val(Mid(.Value, i, 1))
Next i
ccCheck = tmp Mod 10 = Val(Right(.Value, 1))
End With

End Function

--

HTH

RP
(remove nothere from the email address if mailing direct)


"Stephanie" wrote in message
...
Does anyone know how to do a MOD-10 credit card number check in Excel
2000?
Is there a way to do it using a macro and Visual Basic?