Quote Originally Posted by jason_kelly View Post
...check and see if an existing value in Cell A, starting from Cell A2 downwards already exists, (eg. 2010-000001).

If (2010-000001) already exists, then go ahead and input a new number: 2010-000002 and so fourth.
Basically, I have a userform designed, and when I click on "Add a Record" it would then populate the Cell A3 with the new value (eg. 2010-000002)
The first part of your description (first quote) isn't clear when I look at the second part of your description (second quote).

In the first part, it looks like you are checking a value in a cell, and if it exists in any other rows, change it to a new number that doesn't yet exist.

In the second part, it looks like you are simply generating a new number to use in the last row, period.

Do numbers appear multiple times in your sheet? Are they sorted in any particular way? Can you attach a sample?

The second part is clearer. Because the "-" embedded in your serial number makes it a string instead of a number, that adds a little bit of extra work. I would suggest you create a hidden sheet to store the latest serial number (the part after the year), and to create a new serial number increment it and concatenate to "2010-". You will need some additional code to handle the year rollover (I am assuming that it's not just a coincidence that the numbers start with "2010").