Arana's approach (concatenating the lookup parameters) is going to be the fastest when you have a large lookup table. The speed will be up to a thousand times faster doing it that way when you use Office 365 compared to Excel 2016 perpetual (or earlier) because Microsoft is now indexing the lookup column.
I see the point you are making, and understand, but how can it handle the new criteria around the funkiness of how they are using AMOUNT/NUMBER (different from original question before)
Also, a bit complicated as the data set comes from a database/data connection, which I now would need to "edit"post refresh with vba or something (still better than a crashing sheet)
newparadigmz
ASKER
This can be workable, but why am I getting any/wrong answers for the cells in red, they "should" be N/A.
byundt
You omitted the last parameter on the VLOOKUP. It should be either FALSE or 0, just before the rightmost parenthesis.
Without that parameter, Excel assumes your lookup table is sorted in ascending order by its first column and gives you an approximate match.