If the button is clicked by the user, then the active sheet should be saved as a new workbook with the naming convention: SheetName_(CustomerNo_DD.MM.YYYY)
• Create a (hidden) row at the bottom of the invoice with Invoice number, Invoice date, Customer number and Invoice total
• Copy the row at the bottom of the invoice to the next available row in Sheet 7

Sub CopyWS()
Dim No As String

nom = Range("C8").Value & Day(Date) & Month(Date) & Year(Date) & "Invoice" & ActiveWorkbook.Name
ActiveWorkbook.SaveCopyAs ActiveWorkbook.Path & "\" & nom
rep = MsgBox("Your database has been saved : " & Name, vbYesNo + vbInformation, "Copy of spreadsheet")
End Sub