次のコードは正常に動作していますが、保存された値を最も近いペンスに丸めていません。
Public Function Fs_Update_AccInvoices_Nexum() As Boolean
    Dim adoRsInvoiceDCID As New ADODB.Recordset
    Dim adoRsNexumInvoices As New ADODB.Recordset
    On Error Resume Next
    adoRsInvoiceDCID.Open "SELECT * FROM [tInvoiceDCID] where Issued=0" _
        , CurrentProject.Connection, 2, 2
    While Not adoRsInvoiceDCID.EOF
        adoRsNexumInvoices.Open "SELECT * FROM [tPrintInvoiceNumbersNexum] " _
            & " WHERE InvoiceID=" & adoRsInvoiceDCID("InvoiceID") _
            , CurrentProject.Connection, 2, 2
        If Not adoRsNexumInvoices.EOF Then
            DoCmd.SetWarnings off
            DoCmd.RunSQL "Update [Acc Invoices t Nexum] " _
                & " SET [Total Due] = Round((Fees/0.8)+(VAT/0.8)+OutLays,2)" _
                & " Fees = Round(Fees/0.8,2), VAT = Round(Vat/0.8,2)" _
                & " WHERE Invoice=" & adoRsNexumInvoices("PrintingasINVOICE")
        End If
        adoRsNexumInvoices.Close
        adoRsInvoiceDCID.MoveNext
    Wend
    adoRsInvoiceDCID.Close
End Function
乾杯ロス