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 41b298a6e..d46c15b29 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
@@ -160,7 +160,7 @@ public class ExternalCompany extends BaseEntity {
         }
     }
 
-    @AssertTrue(message="company NIF has to be unique. It is already used")
+    @AssertTrue(message="Company ID already used. It has to be be unique")
     public boolean checkConstraintUniqueNif() {
         IExternalCompanyDAO dao = Registry.getExternalCompanyDAO();
 
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Worker.java b/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Worker.java
index dc0699a81..ac04c80e7 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Worker.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Worker.java
@@ -130,7 +130,7 @@ public class Worker extends Resource implements Comparable {
         return getSurname() + ", " + getFirstName();
     }
 
-    @NotEmpty(message="worker's NIF not specified")
+    @NotEmpty(message="Worker ID cannot be empty")
     public String getNif() {
         return nif;
     }
diff --git a/navalplanner-webapp/src/main/resources/i18n/es.po b/navalplanner-webapp/src/main/resources/i18n/es.po
index a160e8b4e..4825adbc4 100644
--- a/navalplanner-webapp/src/main/resources/i18n/es.po
+++ b/navalplanner-webapp/src/main/resources/i18n/es.po
@@ -3420,7 +3420,7 @@ msgid " {0}s"
 msgstr " {0}s"
 
 #: navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Worker.java:133
-msgid "worker's NIF not specified"
+msgid "Worker ID cannot be empty"
 msgstr "NIF del trabajador no especificado"
 
 #: navalplanner-webapp/src/main/webapp/planner/main.zul:60
@@ -4899,8 +4899,8 @@ msgid "The code cannot be empty."
 msgstr "El código no puede estar vacío"
 
 #: navalplanner-business/src/main/java/org/navalplanner/business/externalcompanies/entities/ExternalCompany.java:163
-msgid "company NIF has to be unique. It is already used"
-msgstr "el NIF de la empresa debe ser único. Ya está siendo usado"
+msgid "Company ID already used. It has to be be unique"
+msgstr "NIF de la empresa ya está siendo usado. Debe ser único"
 
 #: navalplanner-webapp/src/main/webapp/resources/machine/_machineConfigurationUnits.zul:34
 msgid "Human hours per machine working hour within configuration unit"
@@ -5403,9 +5403,12 @@ msgstr "Imborrable"
 #: navalplanner-webapp/src/main/webapp/resources/worker/_edition.zul:71
 #: navalplanner-webapp/src/main/webapp/resources/worker/_list.zul:36
 #: navalplanner-webapp/src/main/webapp/resources/criterions/_workers.zul:28
-#: navalplanner-webapp/src/main/webapp/externalcompanies/_listExternalCompanies.zul:26
-#: navalplanner-webapp/src/main/webapp/externalcompanies/_editExternalCompany.zul:45
-msgid "NIF"
+msgid "ID"
+msgstr "NIF"
+
+#: navalplanner-webapp/src/main/webapp/externalcompanies/_listExternalCompanies.zul:52
+#: navalplanner-webapp/src/main/webapp/externalcompanies/_editExternalCompany.zul:106
+msgid "Company ID"
 msgstr "NIF"
 
 #: navalplanner-webapp/src/main/java/org/navalplanner/web/planner/reassign/ReassignCommand.java:168
diff --git a/navalplanner-webapp/src/main/resources/i18n/gl.po b/navalplanner-webapp/src/main/resources/i18n/gl.po
index 9d5d5d2df..43aff252e 100644
--- a/navalplanner-webapp/src/main/resources/i18n/gl.po
+++ b/navalplanner-webapp/src/main/resources/i18n/gl.po
@@ -3406,7 +3406,7 @@ msgid " {0}s"
 msgstr " {0}s"
 
 #: navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Worker.java:133
-msgid "worker's NIF not specified"
+msgid "Worker ID cannot be empty"
 msgstr "NIF do traballador non especificado"
 
 #: navalplanner-webapp/src/main/webapp/planner/main.zul:60
@@ -4881,8 +4881,8 @@ msgid "The code cannot be empty."
 msgstr "O código non pode estar baleiro"
 
 #: navalplanner-business/src/main/java/org/navalplanner/business/externalcompanies/entities/ExternalCompany.java:163
-msgid "company NIF has to be unique. It is already used"
-msgstr "o NIF da empresa debe ser único. Xa está a ser usado"
+msgid "Company ID already used. It has to be be unique"
+msgstr "NIF da empresa xa está sendo usado. Debe ser único"
 
 #: navalplanner-webapp/src/main/webapp/resources/machine/_machineConfigurationUnits.zul:34
 msgid "Human hours per machine working hour within configuration unit"
@@ -5384,9 +5384,12 @@ msgstr "Imborrable"
 #: navalplanner-webapp/src/main/webapp/resources/worker/_edition.zul:71
 #: navalplanner-webapp/src/main/webapp/resources/worker/_list.zul:36
 #: navalplanner-webapp/src/main/webapp/resources/criterions/_workers.zul:28
-#: navalplanner-webapp/src/main/webapp/externalcompanies/_listExternalCompanies.zul:26
-#: navalplanner-webapp/src/main/webapp/externalcompanies/_editExternalCompany.zul:45
-msgid "NIF"
+msgid "ID"
+msgstr "NIF"
+
+#: navalplanner-webapp/src/main/webapp/externalcompanies/_listExternalCompanies.zul:52
+#: navalplanner-webapp/src/main/webapp/externalcompanies/_editExternalCompany.zul:106
+msgid "Company ID"
 msgstr "NIF"
 
 #: navalplanner-webapp/src/main/java/org/navalplanner/web/planner/reassign/ReassignCommand.java:168
diff --git a/navalplanner-webapp/src/main/resources/i18n/keys.pot b/navalplanner-webapp/src/main/resources/i18n/keys.pot
index 97d837135..d9cbbeae8 100644
--- a/navalplanner-webapp/src/main/resources/i18n/keys.pot
+++ b/navalplanner-webapp/src/main/resources/i18n/keys.pot
@@ -3345,7 +3345,7 @@ msgid " {0}s"
 msgstr ""
 
 #: navalplanner-business/src/main/java/org/navalplanner/business/resources/entities/Worker.java:133
-msgid "worker's NIF not specified"
+msgid "Worker ID cannot be empty"
 msgstr ""
 
 #: navalplanner-webapp/src/main/webapp/planner/main.zul:60
@@ -4794,7 +4794,7 @@ msgid "The code cannot be empty."
 msgstr ""
 
 #: navalplanner-business/src/main/java/org/navalplanner/business/externalcompanies/entities/ExternalCompany.java:163
-msgid "company NIF has to be unique. It is already used"
+msgid "Company ID already used. It has to be be unique"
 msgstr ""
 
 #: navalplanner-webapp/src/main/webapp/resources/machine/_machineConfigurationUnits.zul:34
@@ -5277,9 +5277,12 @@ msgstr ""
 #: navalplanner-webapp/src/main/webapp/resources/worker/_edition.zul:71
 #: navalplanner-webapp/src/main/webapp/resources/worker/_list.zul:36
 #: navalplanner-webapp/src/main/webapp/resources/criterions/_workers.zul:28
+msgid "ID"
+msgstr ""
+
 #: navalplanner-webapp/src/main/webapp/externalcompanies/_listExternalCompanies.zul:26
 #: navalplanner-webapp/src/main/webapp/externalcompanies/_editExternalCompany.zul:45
-msgid "NIF"
+msgid "Company ID"
 msgstr ""
 
 #: navalplanner-webapp/src/main/java/org/navalplanner/web/planner/reassign/ReassignCommand.java:168
diff --git a/navalplanner-webapp/src/main/webapp/externalcompanies/_editExternalCompany.zul b/navalplanner-webapp/src/main/webapp/externalcompanies/_editExternalCompany.zul
index f1caab6ef..50272c037 100644
--- a/navalplanner-webapp/src/main/webapp/externalcompanies/_editExternalCompany.zul
+++ b/navalplanner-webapp/src/main/webapp/externalcompanies/_editExternalCompany.zul
@@ -42,7 +42,7 @@
                                     constraint="no empty:${i18n:_('cannot be null or empty')}"/>
                             </row>
                             <row>
-                                <label value="${i18n:_('NIF')}:" />
+                                <label value="${i18n:_('Company ID')}:" />
                                 <textbox id="nif"
                                     value="@{controller.company.nif}"
                                     constraint="no empty:${i18n:_('cannot be null or empty')}"/>
diff --git a/navalplanner-webapp/src/main/webapp/externalcompanies/_listExternalCompanies.zul b/navalplanner-webapp/src/main/webapp/externalcompanies/_listExternalCompanies.zul
index db8cfb11a..3d0b8ecc0 100644
--- a/navalplanner-webapp/src/main/webapp/externalcompanies/_listExternalCompanies.zul
+++ b/navalplanner-webapp/src/main/webapp/externalcompanies/_listExternalCompanies.zul
@@ -23,7 +23,7 @@
         pageSize="10">
         <columns sizable="true">
             <newdatasortablecolumn label="${i18n:_('Name')}" sort="auto(lower(name))" />
-            <newdatasortablecolumn label="${i18n:_('NIF')}" />
+            <newdatasortablecolumn label="${i18n:_('Company ID')}" />
             <newdatasortablecolumn label="${i18n:_('Client')}" />
             <newdatasortablecolumn label="${i18n:_('Subcontractor')}" />
             <newdatasortablecolumn label="${i18n:_('Integrated user')}" />
diff --git a/navalplanner-webapp/src/main/webapp/resources/criterions/_workers.zul b/navalplanner-webapp/src/main/webapp/resources/criterions/_workers.zul
index 98c39db1b..8c1c5ab40 100644
--- a/navalplanner-webapp/src/main/webapp/resources/criterions/_workers.zul
+++ b/navalplanner-webapp/src/main/webapp/resources/criterions/_workers.zul
@@ -25,7 +25,7 @@
    <column label="${i18n:_('Operations')}" />
    <column label="${i18n:_('Name')}" sort="auto(lower(firstName))" />
    <column label="${i18n:_('Surname')}" sort="auto(lower(surname))" />
-   <column label="${i18n:_('NIF')}" sort="auto(nif)" />
+   <column label="${i18n:_('ID')}" sort="auto(nif)" />
   </columns>
   <rows>
    <row self="@{each='worker'}" value="@{worker}">
diff --git a/navalplanner-webapp/src/main/webapp/resources/worker/_edition.zul b/navalplanner-webapp/src/main/webapp/resources/worker/_edition.zul
index 67ae457ef..3a0681049 100644
--- a/navalplanner-webapp/src/main/webapp/resources/worker/_edition.zul
+++ b/navalplanner-webapp/src/main/webapp/resources/worker/_edition.zul
@@ -68,7 +68,7 @@
                                 value="@{controller.worker.surname}" constraint="no empty" width="500px"/>
                         </row>
                         <row visible="@{controller.isRealWorker}">
-                            <label value="${i18n:_('NIF')}" />
+                            <label value="${i18n:_('ID')}" />
                             <textbox value="@{controller.worker.nif}" constraint="no empty"/>
                         </row>
                         <row visible="@{controller.isRealWorker}">
diff --git a/navalplanner-webapp/src/main/webapp/resources/worker/_list.zul b/navalplanner-webapp/src/main/webapp/resources/worker/_list.zul
index a487de62b..6ad956500 100644
--- a/navalplanner-webapp/src/main/webapp/resources/worker/_list.zul
+++ b/navalplanner-webapp/src/main/webapp/resources/worker/_list.zul
@@ -33,7 +33,7 @@
         <columns>
             <newdatasortablecolumn label="${i18n:_('Surname')}" sort="auto(lower(surname))" sortDirection="ascending" />
             <newdatasortablecolumn label="${i18n:_('First name')}" sort="auto(lower(firstName))" />
-            <newdatasortablecolumn label="${i18n:_('NIF')}" sort="auto(nif)" />
+            <newdatasortablecolumn label="${i18n:_('ID')}" sort="auto(nif)" />
             <newdatasortablecolumn label="${i18n:_('Code')}"/>
             <newdatasortablecolumn label="${i18n:_('Limiting')}" sort="auto(limitingResource)" width="90px"/>
             <newdatasortablecolumn label="${i18n:_('Operations')}" width="90px"/>