Searching for Duplicate Text in a column

[Guest]

I have created a worksheet that lists identification numbers for valves and
instruments on filtration machines. Now these identification numbers are
unique because they are a combination of both letters, number and characters.
I need to find a way to check if any of these indentifaciton numbers have
been duplicated in a column. No 2 numbers are the same and again I need to
know how I could check a column in excel for possible duplicates to correct
them.

Thanks

 

[robotman]

you can use MATCH to do a self-look up. If it comes back with a match,
it will tell you where the duplicate is.

Next to your part number do:

=MATCH(item_ID, Range_of_IDs, 0)

Good luck!

 

[Guest]

Another way to play it ..

Assuming source data is running in A2 down

Place in B2:
=IF(A2="","",IF(COUNTIF($A$2:A2,A2)>1,"dup",""))
Copy B2 down as far as required

Col B will flag duplicates in col A as "dup".
We could then easily autofilter* on col B for closer inspection of the "dup".
*Data > Filter > Autofilter