hi,
if your numbers are all in one row or column, you could use this formula
=max(A1:IV1)+1 or = max(A1:A5000)+1
this would get the largest number in the array and add 1 to it ie display
the next number.
but if your data is scattered perticularly between sheets, check out Gord's
suggestion.

regards
FSt1

"nexor63" wrote:

I have created a workbook with several worksheets contaning diferent
information concerning my clients. On 1 sheet I have a list of invoice
numbers starting with 1001 in row A! with relevant info of each invoice being
generated, this is to keep record of all invoices gone out, My own invoice is
in the same workbook but on another worksheet.
I need a formula that can generate the next available invoice number to
prevent duplicating invoice numbers.

Your assistance wil be highly appreciated.