You might be able to use something like this:
=IF(RIGHT(A3,5)<RIGHT(A2,5)+1,"Missing Number","")
assuming that the numeric part is always the last 5 characters


Sheila
"Chet-a-roo" wrote:

I have a large list of serial numbers like (1AW15648). I need to identify
numbers that are missing.

Thanks,

Chet Sheetz

PS I am using Excel 2003