I have exhausted my knowledge of Excel and need some help.

I am trying to compare two columns of data to find duplicates. We will call them column A and column B.

#1 When I try to match column A to column B it finds some matches but misses quit a few
#2 If I try to match column B to column A it finds the ones that #1 misses but misses the ones that #1 found.

I have no idea why this is happening.

FYI… I typically use the match formula: if(iserror(match(A2,B:B,0)),””,1) to find duplicates. However, I have also tried COUNTIF with the same result. I have checked to make sure that both columns use the same data type and I have trimmed.

Any suggestions would be greatly appreciated.