var client = new IeBizServiceClient();
SecurityToken securityToken = new SecurityToken();
Customer customer = new Customer();
securityToken.UserId = "";
securityToken.SecurityId = "1dc496d1-90b4-4a38-ad78-28a795af78e7";
securityToken.Password = "";

  Invoice invoice = new Invoice();
                    invoice.CustomerId = "C-E&000002";
                    invoice.SubCustomerId = "";
                    invoice.InvoiceNumber = "00102565";
                    invoice.InvoiceDate = "04/02/2016";
                    invoice.InvoiceDueDate = "08/12/2016";
                    invoice.InvoiceAmount = (decimal)2000.45;
                    invoice.AmountDue = (decimal)200.45;
                    invoice.DivisionId = "001";
                    invoice.PoNum = "Po001";
                    invoice.SoNum = "";


                    Item[] Lineitems = new Item[1];
                    Item item = new Item();
                    item.ItemId = "001";
                    item.Name = "Orange";
                    item.Description = "Orange";
                    item.Qty = 1;
                    item.UnitPrice = (decimal)200.25;
                    item.UnitOfMeasure = "EA";
                    item.Taxable = true;
                    item.TaxRate = (decimal)8.00;
                    item.TotalLineTax = (decimal)5.25;
                    item.TotalLineAmount = (decimal)205.25;
                    item.ItemLineNumber = 1;
                    Lineitems[0] = item;

                    invoice.Items = Lineitems;
 InvoiceResponse Response = client.AddInvoice(securityToken, invoice);

Console.WriteLine(Response.Status);
Console.WriteLine(Response.StatusCode);
Console.WriteLine(Response.Error);
Console.WriteLine(Response.ErrorCode);

Request:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ebiz="http://eBizCharge.ServiceModel.SOAP">
   <soapenv:Header/>
   <soapenv:Body>
      <ebiz:AddInvoice>
         <ebiz:securityToken>
            <ebiz:SecurityId>1dc496d1-90b4-4a38-ad78-28a795af78e9</ebiz:SecurityId>
            <ebiz:UserId/>
            <ebiz:Password/>
         </ebiz:securityToken>
         <ebiz:invoice>
            <ebiz:CustomerId>CBS</ebiz:CustomerId>
            <ebiz:SubCustomerId/>
            <ebiz:InvoiceNumber>Inv1-011</ebiz:InvoiceNumber>
            <ebiz:InvoiceDate>2017-01-01</ebiz:InvoiceDate>
            <ebiz:Currency>USD</ebiz:Currency>
            <ebiz:InvoiceAmount>1000.00</ebiz:InvoiceAmount>
            <ebiz:InvoiceDueDate>2016-04-02</ebiz:InvoiceDueDate>
            <ebiz:AmountDue>5</ebiz:AmountDue>
            <ebiz:PoNum>PO001</ebiz:PoNum>
            <ebiz:SoNum>SO001</ebiz:SoNum>
            <ebiz:DivisionId>0001</ebiz:DivisionId>
            <ebiz:TypeId>Invoice</ebiz:TypeId>
            <ebiz:Items>
               <ebiz:Item>
                  <ebiz:ItemId>01-00097</ebiz:ItemId>
                  <ebiz:Name>01-00097</ebiz:Name>
                  <ebiz:Description>Wall Mounted Vent-free Gas Fireplace</ebiz:Description>
                  <ebiz:UnitPrice>20.25</ebiz:UnitPrice>
                  <ebiz:Qty>10.00</ebiz:Qty>
                  <ebiz:Taxable>true</ebiz:Taxable>
                  <ebiz:TaxRate>0</ebiz:TaxRate>
                  <ebiz:UnitOfMeasure>EA</ebiz:UnitOfMeasure>
                  <ebiz:TotalLineAmount>200.25</ebiz:TotalLineAmount>
                  <ebiz:TotalLineTax>10.00</ebiz:TotalLineTax>
                  <ebiz:ItemLineNumber>1</ebiz:ItemLineNumber>
               </ebiz:Item>
               <ebiz:Item>
                  <ebiz:ItemId>Orange</ebiz:ItemId>
                  <ebiz:Name>Orange</ebiz:Name>
                  <ebiz:Description>Orange County CA Sales Tax</ebiz:Description>
                  <ebiz:ItemLineNumber>2</ebiz:ItemLineNumber>
               </ebiz:Item>
            </ebiz:Items>
            <ebiz:Software>QuickBooks</ebiz:Software>
            <ebiz:NotifyCustomer>false</ebiz:NotifyCustomer>
            <ebiz:EmailTemplateID/>
            <ebiz:InvoiceURL>https://www.ebizcharge.net/uploads/invoice001.pdf</ebiz:InvoiceURL>
            <ebiz:TotalTaxAmount>10.00</ebiz:TotalTaxAmount>
            <ebiz:InvoiceUniqueId>x123-456-123</ebiz:InvoiceUniqueId>
         </ebiz:invoice>
      </ebiz:AddInvoice>
   </soapenv:Body>
</soapenv:Envelope>


Response:

<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
   <s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
      <AddInvoiceResponse xmlns="http://eBizCharge.ServiceModel.SOAP">
         <AddInvoiceResult>
            <Status>Success</Status>
            <StatusCode>1</StatusCode>
            <Error/>
            <ErrorCode>0</ErrorCode>
         </AddInvoiceResult>
      </AddInvoiceResponse>
   </s:Body>
</s:Envelope>