Conditional Formatting to compare 2 columns, and identify future repeats

[skittlz]

Hi, I have 2 columns - Column A has Equipment Names, and Column B has equipment number (each equipment name serialized - 1, 2, 3, 4, and so on). I need to conditionally format the 2 columns so that if there are duplicates of the SN for a given Equipment Name, it would flag it as red.

For example, this is ok:

This is not ok:

How can I do that? Please help!

There are thousands of entries in random order, so hopefully conditional formatting can manage that without slowing down!

Thank you!

 

[Fluff]

Select B2 down & use this formula

=COUNTIFS(A:A,A2,B:B,B2)>1

 

[HighAndWilder]

Hi, I have 2 columns - Column A has Equipment Names, and Column B has equipment number (each equipment name serialized - 1, 2, 3, 4, and so on). I need to conditionally format the 2 columns so that if there are duplicates of the SN for a given Equipment Name, it would flag it as red.

For example, this is ok:

View attachment 119182

This is not ok:

View attachment 119183

How can I do that? Please help!

There are thousands of entries in random order, so hopefully conditional formatting can manage that without slowing down!

Thank you!

This from Leila Gharani will help you. You have a number of options.

Excel Find and Highlight Duplicates