Take a look at

http://www.mcgimpsey.com/excel/sequentialnums.html

In article ,
"thecashman" wrote:

How can I set up automatic sequential invoice numbering across multiple
worksheets but in the same workbood? I have all my customers set up on
individual worksheets and would like to assign an invoice number when I
print. Then would like the next time I print possibly a different worksheet
to print the next number up from the previous number that was assigned to the
last invoice.