Hi

Try

Code:
Option Explicit

Sub kTest()
    
    Dim x, K1 As Range, K2, i As Long, r As Long
    
    Set K1 = Sheet1.Range("a1").CurrentRegion.Columns(1)
    K2 = Sheet2.Range("a1").CurrentRegion.Value2
    
    r = K1.Rows.Count
    For i = 2 To UBound(K2, 1)
        x = Application.Match(K2(i, 1), K1.Value2, 0)
        If IsError(x) Then
            K1.Cells(1).Offset(r).Resize(, UBound(K2, 2)) = Application.Index(K2, i, 0)
            r = r + 1
        End If
    Next
    
End Sub