diff --git a/src/org/openbravo/contract/services/process/billing/StandardContractInvoiceProcess.java b/src/org/openbravo/contract/services/process/billing/StandardContractInvoiceProcess.java
--- a/src/org/openbravo/contract/services/process/billing/StandardContractInvoiceProcess.java
+++ b/src/org/openbravo/contract/services/process/billing/StandardContractInvoiceProcess.java
@@ -1,5 +1,5 @@
 /************************************************************************************ 
- * Copyright (C) 2012-2013 Openbravo S.L.U.
+ * Copyright (C) 2012-2015 Openbravo S.L.U.
  * Licensed under the Openbravo Commercial License version 1.0
  * You may obtain a copy of the License at http://www.openbravo.com/legal/obcl.html
  * or in the legal folder of this module distribution.
@@ -690,7 +690,8 @@
         TaxRate taxRate = dao.C_GETTAX(product.getId(), invoiceTemp.getInvoiceDate(),
             invoicePlanItem.getOrganization().getId(), null, invoicePlanItem.getProject()
                 .getPartnerAddress().getId(), invoicePlanItem.getProject().getPartnerAddress()
-                .getId(), null, true);
+                .getId(), null, invoicePlanItem.getProject().getOBCNTRContractType()
+                .isSalesContract());
 
         if (taxRate == null) {
           throw new OBException("No tax found for product (" + product.getName() + "), ship date ("
@@ -699,7 +700,8 @@
               + "), warehouse (null), business partner address ("
               + invoicePlanItem.getProject().getPartnerAddress().getName() + "), invoice address ("
               + invoicePlanItem.getProject().getPartnerAddress().getName()
-              + "), project (null), isSalesTransaction (true)");
+              + "), project (null), isSalesTransaction ("
+              + invoicePlanItem.getProject().getOBCNTRContractType().isSalesContract() + ")");
         }
 
         // Calculate Accruals and Deferrals Plan from Product