diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/externalcompanies/entities/ExternalCompany.java b/navalplanner-business/src/main/java/org/navalplanner/business/externalcompanies/entities/ExternalCompany.java
index 849fdcc98..9bce155e9 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/externalcompanies/entities/ExternalCompany.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/externalcompanies/entities/ExternalCompany.java
@@ -20,6 +20,7 @@
 
 package org.navalplanner.business.externalcompanies.entities;
 
+import org.apache.commons.lang.StringUtils;
 import org.hibernate.validator.AssertTrue;
 import org.hibernate.validator.NotEmpty;
 import org.navalplanner.business.common.BaseEntity;
@@ -175,4 +176,16 @@ public class ExternalCompany extends BaseEntity {
             }
         }
     }
-}
+
+    @AssertTrue(message = "interaction fields are empty and company is marked as interact with applications")
+    public boolean checkConstraintInteractionFieldsNotEmptyIfNeeded() {
+        if (!interactsWithApplications) {
+            return true;
+        }
+
+        return !StringUtils.isEmpty(appURI)
+                && !StringUtils.isEmpty(ourCompanyLogin)
+                && !StringUtils.isEmpty(ourCompanyPassword);
+    }
+
+}
\ No newline at end of file
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/SubcontractedTaskData.java b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/SubcontractedTaskData.java
index 39c87f0a3..fc8a8105b 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/SubcontractedTaskData.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/SubcontractedTaskData.java
@@ -23,6 +23,7 @@ package org.navalplanner.business.planner.entities;
 import java.math.BigDecimal;
 import java.util.Date;
 
+import org.hibernate.validator.AssertTrue;
 import org.hibernate.validator.NotNull;
 import org.navalplanner.business.common.BaseEntity;
 import org.navalplanner.business.externalcompanies.entities.ExternalCompany;
@@ -220,4 +221,17 @@ public class SubcontractedTaskData extends BaseEntity {
         this.criterionRequirementsExported = subcontratedTask.criterionRequirementsExported;
     }
 
+    @AssertTrue(message = "external company should be subcontractor")
+    public boolean checkConstraintExternalCompanyIsSubcontractor() {
+        if (!firstLevelValidationsPassed()) {
+            return true;
+        }
+
+        return externalCompany.isSubcontractor();
+    }
+
+    private boolean firstLevelValidationsPassed() {
+        return (externalCompany != null) && (subcontratationDate != null);
+    }
+
 }
\ No newline at end of file
diff --git a/navalplanner-business/src/test/java/org/navalplanner/business/test/planner/daos/TaskElementDAOTest.java b/navalplanner-business/src/test/java/org/navalplanner/business/test/planner/daos/TaskElementDAOTest.java
index c40812fe8..e65eeba61 100644
--- a/navalplanner-business/src/test/java/org/navalplanner/business/test/planner/daos/TaskElementDAOTest.java
+++ b/navalplanner-business/src/test/java/org/navalplanner/business/test/planner/daos/TaskElementDAOTest.java
@@ -427,9 +427,11 @@ public class TaskElementDAOTest {
     @Autowired
     private IExternalCompanyDAO externalCompanyDAO;
 
-    private ExternalCompany getExternalCompanySaved() {
+    private ExternalCompany getSubcontractorExternalCompanySaved() {
         ExternalCompany externalCompany = ExternalCompanyDAOTest
                 .createValidExternalCompany();
+        externalCompany.setSubcontractor(true);
+
         externalCompanyDAO.save(externalCompany);
         externalCompanyDAO.flush();
         sessionFactory.getCurrentSession().evict(externalCompany);
@@ -446,7 +448,7 @@ public class TaskElementDAOTest {
 
         SubcontractedTaskData subcontractedTaskData = SubcontractedTaskData
                 .create();
-        subcontractedTaskData.setExternalCompany(getExternalCompanySaved());
+        subcontractedTaskData.setExternalCompany(getSubcontractorExternalCompanySaved());
 
         task.setSubcontractedTaskData(subcontractedTaskData);
         taskElementDAO.save(task);