Cell Validation

markster

Well-known Member
Joined
May 23, 2002
Messages
507
Hello

I need to get someone to enter data in a spreadsheet. They will be entering in column a. I need to fix it so the person entering the data cannot enter duplicate numbers so saying 1234 appears in cell a1, if they try to put the same number in in say a100 it won't let them.

Is this possible? and if so how?

Thanks
 

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Richard Schollar

MrExcel MVP
Joined
Apr 19, 2005
Messages
23,707
1. Select A1:A1000 (or whatever range is appropriate)
2. Go Data>Validation>Allow: Custom and use a formula of:

=COUNTIF($A:$A,$A1)<2

and hit OK.
 
Joined
Jul 30, 2006
Messages
3,656
markster,

Highlite the range, say A1:A1000
Data, Validation, Settings tab, "Allow:" box, pick "Custom", enter into the "Formula:" box, the following formula:
=COUNTIF($A$1:$A$1000,A1)=1

Then enter into two cells:
1234


Have a great day,
Stan
 

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