Cannot change Tax Code of A/R Invoice line

Question

Hello,
I had this small problem where i cannot change the tax code of A/R invoice line.
ARInvoice.Lines.TaxCode = "O1";
But after i added the invoice, it seems that SAP still used the default TaxCode which is X1. Am i missing something? I've been stuck in this problem for over two weeks now.
Thank you, any help will be appreciated.

Answer 1

Here is my SAP Settings.
G/L Account Determination
   Sales - Tax
          Sales Tax Group (Service) = Exempt Output
Business Partner Master Data
   Accounting - Tax
          Tax Status = Liable
And here is my code snippet for creating and adding of A/R Invoice :
SAPbobsCOM.Documents _oARInvoice = (SAPbobsCOM.Documents)this.COMPANY.GetBusinessObject(BoObjectTypes.oInvoices);
            _oARInvoice.CardCode = pCustomerId;
            _oARInvoice.HandWritten = BoYesNoEnum.tNO;
            _oARInvoice.DocDate = pPostingDate;
            _oARInvoice.DocDueDate = pPostingDate;
double _total = 0;
            if (pInvoiceType == SAPVariables.INVOICETYPE.SERVICE)
                _oARInvoice.DocType = BoDocumentTypes.dDocument_Service;
                for (int i = 0; i < pARInvoice.Rows.Count; i++)
                    if (i > 0) _oARInvoice.Lines.Add();
                    _oARInvoice.Lines.SetCurrentLine(i);
                    _oARInvoice.Lines.ItemDescription = pARInvoice.Rows<i>["SERVICEDESCRIPTION"].ToString();
                    _oARInvoice.Lines.AccountCode = pARInvoice.Rows<i>["GLACCOUNT"].ToString();
                    double _discountPercent = 0;
                    double.TryParse(pARInvoice.Rows<i>["DISCOUNTPERCENT"].ToString(), out _discountPercent);
                    _oARInvoice.Lines.DiscountPercent = _discountPercent;                   
                    double _lineTotal = 0;
                    double.TryParse(pARInvoice.Rows<i>["AMOUNT"].ToString(), out _lineTotal);
                   // This part here, does not reflect in SAP
                    if (_lineTotal >= 2500000)
                        _oARInvoice.Lines.TaxCode = "O1";
                    else
                        _oARInvoice.Lines.TaxCode = "X0";
                    _oARInvoice.Lines.PriceAfterVAT = _lineTotal;                   
                    _total += _lineTotal;
else
                this.ERRORMESSAGE = "Invalid Invoice Type.";
                throw new Exception("Invalid Invoice Type.");
            _oARInvoice.DocTotal = _total;
            _oARInvoice.Comments = pComments;
            this.LASTINSERTINVOICEID = "";
            this.RETURNCODE = _oARInvoice.Add();
            if (this.RETURNCODE != 0)
                int _tempErrorCode = 0;
                string _tempErrorString = "";
                this.COMPANY.GetLastError(out _tempErrorCode, out _tempErrorString);
                this.ERRORCODE = _tempErrorCode;
                this.ERRORMESSAGE = _tempErrorString;
                _result = false;
            else
                this.RECORDSET = (SAPbobsCOM.Recordset)this.COMPANY.GetBusinessObject(SAPbobsCOM.BoObjectTypes.BoRecordset);
                this.RECORDSET.DoQuery("SELECT MAX(DocEntry) FROM OINV");
                this.LASTINSERTINVOICEID = this.RECORDSET.Fields.Item(0).Value.ToString();
                _result = true;