I am having problems with using the vlookup function in that the results I was expecting are not coming true on every occassion. If I make a very simple table in Sheet1 so that A1 has ABCD and A2 has EFGH and B1 has 10 and B2 has 20. If I then go to Sheet2 and enter in B1 =vlookup($A1,Sheet1!$A1:$B2,2) and then in A1 I enter ABCD I get the result of 10 which is correct but if I enter AXXD I am still getting 10 as a result instead of a zero or #N/A. Presumably it is not looking for an exact match but something similar - could someone give me some advice please?