diff --git a/TapSchemaManagerWebApp/pom.xml b/TapSchemaManagerWebApp/pom.xml
index 8f3e7088f4c03fb487122f118c803e34982a2e3f..8926c58e27d6682427a372fa6b4a7f3e9db76c75 100644
--- a/TapSchemaManagerWebApp/pom.xml
+++ b/TapSchemaManagerWebApp/pom.xml
@@ -4,7 +4,7 @@
 
     <groupId>it.inaf.ia2.tap</groupId>
     <artifactId>TapSchemaManagerWebApp</artifactId>
-    <version>1.0.1</version>
+    <version>1.0.2</version>
     <packaging>war</packaging>
 
     <name>TapSchemaManagerWebApp</name>
@@ -87,7 +87,7 @@
         <dependency>
             <groupId>it.inaf.ia2.tap</groupId>
             <artifactId>TapSchemaManagerAPI</artifactId>
-            <version>1.0.1</version>
+            <version>1.0.2</version>
         </dependency>
         <dependency>
             <groupId>ari.ucd</groupId>
@@ -100,6 +100,11 @@
             <version>7.0</version>
             <scope>provided</scope>
         </dependency>
+        <dependency>
+            <groupId>uk.me.nxg</groupId>
+            <artifactId>unity</artifactId>
+            <version>1.0</version>
+        </dependency>
         <dependency>
             <groupId>mysql</groupId>
             <artifactId>mysql-connector-java</artifactId>
diff --git a/TapSchemaManagerWebApp/src/main/java/it/inaf/ia2/tsm/webapp/TapSchemaEditingBean.java b/TapSchemaManagerWebApp/src/main/java/it/inaf/ia2/tsm/webapp/TapSchemaEditingBean.java
index e4753686841a80818d511fd59f986b2b9d339c44..f06737e6b4abe16202a1ea8a0551e36d34560ff8 100644
--- a/TapSchemaManagerWebApp/src/main/java/it/inaf/ia2/tsm/webapp/TapSchemaEditingBean.java
+++ b/TapSchemaManagerWebApp/src/main/java/it/inaf/ia2/tsm/webapp/TapSchemaEditingBean.java
@@ -72,6 +72,7 @@ public class TapSchemaEditingBean implements Serializable {
 
     private EntitiesContainer currentAddingContainer;
     private List<AddableItem> currentAddables;
+    private VOUnitValidator voUnitValidator;
 
     @Inject
     private SearchUCDDialog searchUCDDialog;
@@ -88,6 +89,10 @@ public class TapSchemaEditingBean implements Serializable {
         return selectedColumn;
     }
 
+    public VOUnitValidator getVoUnitValidator() {
+        return voUnitValidator;
+    }
+
     public void setSelectedSchema(Schema selectedSchema) {
         this.selectedSchema = selectedSchema;
         if (selectedSchema == null) {
@@ -118,6 +123,7 @@ public class TapSchemaEditingBean implements Serializable {
 
     public void setSelectedColumn(Column selectedColumn) {
         this.selectedColumn = selectedColumn;
+        selectedColumnChanged();
     }
 
     public UpdateOperations getUpdateOperations() {
@@ -218,6 +224,15 @@ public class TapSchemaEditingBean implements Serializable {
                 }
             }
         }
+        selectedColumnChanged();
+    }
+
+    private void selectedColumnChanged() {
+        if (selectedColumn == null) {
+            voUnitValidator = new VOUnitValidator(null);
+        } else {
+            voUnitValidator = new VOUnitValidator(selectedColumn.getUnit());
+        }
     }
 
     public void setTapSchema(TapSchema tapSchema) {
@@ -328,6 +343,9 @@ public class TapSchemaEditingBean implements Serializable {
 
     public void textInputChanged(TapSchemaEntity entity, String key) {
         final boolean isChanged = entity.isChanged(key);
+        if (key.equals("unit")) {
+            voUnitValidator = new VOUnitValidator(entity.getValue(key, String.class));
+        }
         CustomPartialResponseWriter.getCurrentInstance().addCustomJSUpdate(new JSUpdateHandler() {
 
             @Override
diff --git a/TapSchemaManagerWebApp/src/main/java/it/inaf/ia2/tsm/webapp/VOUnitValidator.java b/TapSchemaManagerWebApp/src/main/java/it/inaf/ia2/tsm/webapp/VOUnitValidator.java
new file mode 100644
index 0000000000000000000000000000000000000000..485681f03e66bec14e3562958dfcb7d4a8be31ff
--- /dev/null
+++ b/TapSchemaManagerWebApp/src/main/java/it/inaf/ia2/tsm/webapp/VOUnitValidator.java
@@ -0,0 +1,89 @@
+/*
+ * _____________________________________________________________________________
+ * 
+ * INAF - OATS National Institute for Astrophysics - Astronomical Observatory of
+ * Trieste INAF - IA2 Italian Center for Astronomical Archives
+ * _____________________________________________________________________________
+ * 
+ * Copyright (C) 2017 Istituto Nazionale di Astrofisica
+ * 
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License Version 3 as published by the
+ * Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ * 
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+package it.inaf.ia2.tsm.webapp;
+
+import java.io.Serializable;
+import uk.me.nxg.unity.Syntax;
+import uk.me.nxg.unity.UnitExpr;
+import uk.me.nxg.unity.UnitParser;
+
+/**
+ * Serializable wrapper for VOUnit UnitExpr
+ *
+ * @author Sonia Zorba <zorba at oats.inaf.it>
+ */
+public class VOUnitValidator implements Serializable {
+
+    private static final long serialVersionUID = -1019359441934896102L;
+
+    private static final Syntax syntax = Syntax.lookup("vounits");
+
+    private final boolean unset;
+    private boolean parsable;
+    private boolean allUnitsRecognised;
+    private boolean allUnitsRecommended;
+    private boolean allUsageConstraintsSatisfied;
+    private String exceptionMessage;
+
+    public VOUnitValidator(String value) {
+
+        unset = value == null || value.isEmpty();
+
+        if (!unset) {
+            try {
+                UnitParser parser = new UnitParser(syntax, value);
+                UnitExpr expr = parser.getParsed();
+                allUnitsRecognised = expr.allUnitsRecognised(syntax);
+                allUnitsRecommended = expr.allUnitsRecommended(syntax);
+                allUsageConstraintsSatisfied = expr.allUsageConstraintsSatisfied(syntax);
+                parsable = true;
+            } catch (Throwable t) {
+                exceptionMessage = t.getMessage();
+            }
+        }
+    }
+
+    public boolean isUnset() {
+        return unset;
+    }
+
+    public boolean isParsable() {
+        return parsable;
+    }
+
+    public boolean isAllUnitsRecognised() {
+        return allUnitsRecognised;
+    }
+
+    public boolean isAllUnitsRecommended() {
+        return allUnitsRecommended;
+    }
+
+    public boolean isAllUsageConstraintsSatisfied() {
+        return allUsageConstraintsSatisfied;
+    }
+
+    public String getExceptionMessage() {
+        return exceptionMessage;
+    }
+}
diff --git a/TapSchemaManagerWebApp/src/main/resources/webapp.properties b/TapSchemaManagerWebApp/src/main/resources/webapp.properties
index 9de6d7dd2faf32f5aaa31edae1925c32499f18a3..74d3e4b1c890d47ec208f0ff07aca0c11da981a5 100644
--- a/TapSchemaManagerWebApp/src/main/resources/webapp.properties
+++ b/TapSchemaManagerWebApp/src/main/resources/webapp.properties
@@ -1,3 +1,3 @@
-ucd_service_url=http://ia2-vo.oats.inaf.it:8080/ucd/
+ucd_service_url=http://ia2-vo.oats.inaf.it/ucd/
 credentials_config_path=/home/sonia/.tsm/config.xml
 password=pippo
\ No newline at end of file
diff --git a/TapSchemaManagerWebApp/src/main/webapp/tapSchemaEditing.xhtml b/TapSchemaManagerWebApp/src/main/webapp/tapSchemaEditing.xhtml
index 113af63e1c8adb02ebb45c9e6ce268f5b601833b..9806f514a58c94283c3292b10dbce525720db97a 100644
--- a/TapSchemaManagerWebApp/src/main/webapp/tapSchemaEditing.xhtml
+++ b/TapSchemaManagerWebApp/src/main/webapp/tapSchemaEditing.xhtml
@@ -314,10 +314,44 @@
                                                             <h:inputText 
                                                                 id="column_unit"
                                                                 class="form-control #{tapSchemaEditing.selectedColumn.isChanged('unit') ? 'changed' : ''}"
-                                                                value="#{tapSchemaEditing.selectedColumn.unit}">
+                                                                value="#{tapSchemaEditing.selectedColumn.unit}"
+                                                                autocomplete="off">
                                                                 <f:converter converterId="it.inaf.ia2.NullOrEmptyConverter" />
-                                                                <f:ajax event="keyup" execute="@form" listener="#{tapSchemaEditing.textInputChanged(tapSchemaEditing.selectedColumn, 'unit')}" onevent="TSM.textInputChanged" />
+                                                                <f:ajax event="keyup" execute="@form" listener="#{tapSchemaEditing.textInputChanged(tapSchemaEditing.selectedColumn, 'unit')}" onevent="TSM.textInputChanged" render="vounit-validator" />
                                                             </h:inputText>
+                                                            <h:panelGroup id="vounit-validator">
+                                                                <h:panelGroup rendered="#{!tapSchemaEditing.voUnitValidator.unset}">
+                                                                    <h:panelGroup rendered="#{tapSchemaEditing.voUnitValidator.parsable}">
+                                                                        <ul>
+                                                                            <li>
+                                                                                all units recognised
+                                                                                <span class="#{tapSchemaEditing.voUnitValidator.allUnitsRecognised ? 'text-success' : 'text-danger'}">
+                                                                                    <span class="glyphicon glyphicon-#{tapSchemaEditing.voUnitValidator.allUnitsRecognised ? 'ok' : 'remove'}"></span>                                                                                
+                                                                                </span>
+                                                                            </li>
+                                                                            <li>
+                                                                                all units recommended
+                                                                                <span class="#{tapSchemaEditing.voUnitValidator.allUnitsRecommended ? 'text-success' : 'text-danger'}">
+                                                                                    <span class="glyphicon glyphicon-#{tapSchemaEditing.voUnitValidator.allUnitsRecommended ? 'ok' : 'remove'}"></span>
+                                                                                </span>
+                                                                            </li>
+                                                                            <li>
+                                                                                all constraints satisfied
+                                                                                <span class="#{tapSchemaEditing.voUnitValidator.allUsageConstraintsSatisfied ? 'text-success' : 'text-danger'}">
+                                                                                    <span class="glyphicon glyphicon-#{tapSchemaEditing.voUnitValidator.allUsageConstraintsSatisfied ? 'ok' : 'remove'}"></span>
+                                                                                </span>
+                                                                            </li>
+                                                                        </ul>
+                                                                    </h:panelGroup>
+                                                                    <h:panelGroup rendered="#{!tapSchemaEditing.voUnitValidator.parsable}">
+                                                                        <p class="text-danger">
+                                                                            <span class="glyphicon glyphicon-remove"></span>
+                                                                            <strong>Invalid VOUnit</strong>:
+                                                                            #{tapSchemaEditing.voUnitValidator.exceptionMessage}
+                                                                        </p>
+                                                                    </h:panelGroup>
+                                                                </h:panelGroup>
+                                                            </h:panelGroup>
                                                         </div>
                                                         <div class="form-group">
                                                             <h:outputLabel for="column_description" class="control-label">Description:</h:outputLabel>