Comparing and finding duplicates on Spreadsheet on two different tabs

[Angela N2 Publishing]

You all rocked my world last time I was faced with a difficult Excel problem, so I'm trying it again!

Is there a way to compare/find duplicates on a spreadsheet on different tabs?

I have a list of September names on one tab, and have an October list of names on a second tab. Eventually, I'll have a November on a third, December on a fourth, etc.

I want a way to indicate/flag names if they've been on previous month's list. Example: If the name was on the September list, I want to flag it on the October list (or highlight).

Make sense? Is that possible? If so, how?

THANKS!

 

[Fluff]

A few questions
1) Are the sheets called September, October etc?
2) What cells are the names in?
3) If a name is on the October & November list but not on the September list, would you want it flagged on the Nov list?

 

[Angela N2 Publishing]

1. Yes, those are the titles of the sheet tabs
2. I would love to be able to flag the names in column B and C ... on all sheets, if possible.
3. Yes, flag it from the previous month regardless of which month.

 

[Fluff]

Are the names in B & C separate, or do they need to be matched as a pair (ie first name & surname)?
If a name is in September, but not October & reappears in November should it still be flagged?

 

[Angela N2 Publishing]

The names in B and C go together - therefore to be flagged together as a unit. (Don't flag if it just says "James" in col B ... instead, flag if it reads "James" in col B and "Smith" in col C)

Yes, it should still be flagged, but I highly doubt that will be the case with the project I'm working on.

THANKS!!!

 

[Fluff]

Ok, how about

Sub AngelaN2()
   Dim Cl As Range
   Dim Dic As Object
   Dim Mnth As String, Vlu As String
   Dim i As Long
   
   Set Dic = CreateObject("scripting.dictionary")
   For i = 9 To 12
      Mnth = MonthName(i)
      If Evaluate("isref('" & Mnth & "'!A1)") Then
         With Sheets(MonthName(i))
            For Each Cl In .Range("B2", .Range("B" & Rows.Count).End(xlUp))
               Vlu = Cl.Value & "|" & Cl.Offset(, 1).Value
               If Not Dic.Exists(Vlu) Then
                  Dic.Add Vlu, Mnth
               Else
                  Cl.Interior.Color = 45678
                  Cl.Offset(, 2).Value = Mnth
               End If
            Next Cl
         End With
      End If
   Next i
End Sub

The line in red will add the first month the name was found into col D. Delete it if not needed.

 

[Angela N2 Publishing]

THANK YOU!! Beautiful CODE!!

 

[Fluff]

My pleasure & thanks for the feedback