 <p>to handle ALL worksheet, place this in ThisWorkbook code pane</p> <pre><code>Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Range) If Not Intersect(Target, Sh.Columns(13)) Is Nothing Then MsgBox "Help Help" End If End Sub </code></pre> <p>or</p> <pre><code>Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Range) If Target.Column = 13 Then MsgBox "Help Help" End If End Sub </code></pre> <p>Otherwise place the following in the code pane of the Sheet(s) you want to "handle" only</p> <pre><code>Private Sub Worksheet_Change(ByVal Target As Range) If Target.Column = 13 Then MsgBox "Help Help" End If End Sub </code></pre>