Hi

Do you want to count the duplicates across the columns or down the columns

assuming that you have col A, B and C for Jan, Feb and Mar
and you want to count the numbers of repeating phone numbers across in Jan,
Feb and Mar. try this =COUNTIF(A2:C2,"1")

if you want to count down the column for duplicates, create a list of unique
phone numbers in a column, say D2 and down, you may use the Advance Filter
for
this and try this in the last empty cell in the column A
=COUNTIF($A$2:$A$14,D2), where D2 hold the first unique number

Adjust the ranges to yours





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Hope this is helpful

Pls click the Yes button below if this post provide answer you have asked

Thank You

cheers, francis

Am not a greek but an ordinary user trying to assist another



"wookie" wrote:

I have 3 months of phone numbers from phone bills and I need to know if
there is a way I can make a formula to show me the duplicate numbers from
month to month. I have input them in 3 columns and not sure what to do from
here. I've been reading on the forum and some of I'm reading is not making
sense. I know how to use the basics of excel but now getting this in depth
I'm not sure what to do.