Попробуйте этот код, пожалуйста. Он основан на предположении, что в исходном листе могут быть ключи, которых нет на вашем «Мастер» листе, которые будут добавлены в первую пустую строку мастер-листа.
Sub testMasterUpdate()
Dim shM As Worksheet, shS As Worksheet, s As Long, boolF As Boolean
Dim lastRM As Long, lastRS As Long, m As Long
Dim arrM As Variant, arrS As Variant, arrDif As Variant, d As Long
Set shM = Worksheets("Master") 'please, use here your sheet name
Set shS = Worksheets("Source") 'please, use here your sheet name
lastRM = shM.Range("A" & Cells.Rows.Count).End(xlUp).Row
lastRS = shS.Range("A" & Cells.Rows.Count).End(xlUp).Row
arrM = shM.Range("A2:A" & lastRM).value
arrS = shS.Range("A2:A" & lastRS).value
ReDim arrDif(1 To 1, 1 To UBound(arrM) + UBound(arrS)): d = 1
For s = 1 To UBound(arrS)
For m = 1 To UBound(arrM)
If arrS(s, 1) = arrM(m, 1) Then
boolF = True
Exit For
End If
Next m
If Not boolF Then
arrDif(1, d) = arrS(s, 1)
d = d + 1
End If
boolF = False
Next s
If d > 1 Then
ReDim Preserve arrDif(1 To 1, 1 To d - 1)
'shM.Range("A" & lastRM + 1).Resize(UBound(arrDif, 2), 1).value = _
WorksheetFunction.Transpose(arrDif)
shM.Range("A" & lastRM).Resize(UBound(arrDif, 2), 1).value = _
WorksheetFunction.Transpose(arrDif)
lastRM = shM.Range("A" & Cells.Rows.Count).End(xlUp).Row
shM.Range("A" & lastRM + 1).Formula = "=CountA(A2:A" & lastRM & ")"
End If
End Sub
Пожалуйста, замените generi c имен листов с вашими настоящими.