Bonjour slijack, forum,
En retouchant légèrement la macro:
Sub Incrémenter_Facture()
Dim num As String, an As String
Dim i As Integer
num = Right(Range("C8").Value, 3) + 1
an = Mid(Range("C8"), 6, 4)
If an = Year(Range("B2")) Then
For i = 1 To 3 - Len(num)
num = "0" & num
Next i
Range("C8").Value = Range("B4") & num
Else
Range("C8").Value = Range("B4") & "001"
End If
End Sub
Amicalement