Macro to Check for Missing Leading Zero

Hi.

Check this code:

Sub VERIFYPHNUM()
    Dim rphnum As Long
    
    rphnum = Range("A" & Rows.Count).End(xlUp).Row
    
    For i = 1 To rphnum
        If Left(Range("A" & i).Value, 1) <> 0 Then
            Range("A" & i) = "0" & Range("A" & i)
        End If
    Next
End Sub