Stock Lists

[warby23]

hi all,

I have created a basi stock list so I can monitor stock coming in and stock going out, this was working fine until I noticed a major flaw in my spreadsheet.
Basically if I scan a stock item out with it's serial number and then scan it back in again my spreadsheet count that as 2 items instead of one and therefore when I perform a stock check my totals do not add up.
I was basically using a countif statement to count cells that contained data but what I really need to do is count cells that contain unique data (if that makes sense!!), If I san a serial number out and then back in again then that serial number is in my list twice, but I only want to count it once, is this possible?

Hope this makes sense, thanks

[martindwilson]

example workbook please !