tweaked a little as second list job number is in column B

but this works perfectly

many thanks

Option Explicit

Private Sub CommandButton3_Click()
Dim lrow As Long

Application.ScreenUpdating = False
Application.DisplayAlerts = False

If Not Evaluate("ISREF(Temp!A1)") Then
    Worksheets.Add(after:=Worksheets(Worksheets.Count)).Name = "Temp"
End If

lrow = Worksheets("JOBSUM_DATA").Range("A" & Rows.Count).End(xlUp).Row
Worksheets("JOBSUM_DATA").Range("A2:A" & lrow).Copy Worksheets("Temp").Range("A2")

lrow = Worksheets("INCOME_DATA").Range("B" & Rows.Count).End(xlUp).Row
Worksheets("INCOME_DATA").Range("B2:B" & lrow).Copy Worksheets("Temp").Range("A" & Rows.Count).End(xlUp).Offset(1, 0)

With Worksheets("Temp")
    .Columns("A:A").RemoveDuplicates Columns:=1, Header:=xlNo
    lrow = .Range("A" & .Rows.Count).End(xlUp).Row
    .Range("A2:A" & lrow).Copy Worksheets("SUMMARY DATA").Range("A2")
    .Delete
End With

Application.ScreenUpdating = True
Application.DisplayAlerts = True

End Sub