Quote Originally Posted by slx
In terms of descending order, it works up until i get to under 100. IDs 1-99 cant seem to be found.
Hmmmm....here's a thought:

Check numbers 1-99. Are they really numbers? or are they text?
If those cells are formatted as "text" or contain text (eg '099) and the VLOOKUP is searching for numbers, those text values won't be recognized.

Does that help?