diff --git a/force-app/main/default/classes/TestDataFactory.cls b/force-app/main/default/classes/TestDataFactory.cls
index 2badf59..f660b85 100644
--- a/force-app/main/default/classes/TestDataFactory.cls
+++ b/force-app/main/default/classes/TestDataFactory.cls
@@ -958,6 +958,26 @@ public class TestDataFactory {
                 && fieldDesc.isCreateable(); // value can be set on creation 
         }
 
+        /**
+        * @description check if a field is unique
+        * @param fieldDesc (Schema.DescribeFieldResult): field describe information
+        * @return true if a value should be unique
+        */
+        @TestVisible
+        private Boolean isUniqueValueRequired(Schema.DescribeFieldResult fieldDesc){
+            return 
+                fieldDesc?.isUnique() == true
+                || fieldDesc?.isExternalID() == true;
+        }
+
+        /**
+        * @description return the unique 6 digits Integer
+        * @return unique Integer
+        */
+        private Integer getUniqueNumber() {
+            return Integer.valueOf(Math.random()*1000000);
+        }
+
         /**
         * @description generate a default value for a given field of an sObject 
         *                       depending on the field type, the corresponding get{FieldType}DefaultValue method will be invoked to retrieve the default value
@@ -1121,7 +1141,7 @@ public class TestDataFactory {
         * @return email default value
         */
         public virtual String getEmailDefaultValue(Schema.DescribeSObjectResult sObjectDesc, Schema.DescribeFieldResult fieldDesc, Integer recordIndex){
-            return 'test'+recordIndex.format()+'@email.com';
+            return 'test'+recordIndex.format()+getUniqueNumber()+'@email.com';
         }
         /**
         * @description get the default value for Geolocation field type
@@ -1191,7 +1211,10 @@ public class TestDataFactory {
         * @return text default value
         */
         public virtual String getTextDefaultValue(Schema.DescribeSObjectResult sObjectDesc, Schema.DescribeFieldResult fieldDesc, Integer recordIndex){
-            return 'test'+recordIndex.format();
+            String textValue = 'test' + recordIndex.format();
+            if (isUniqueValueRequired(fieldDesc)) {
+                textValue = getUniqueNumber() + textValue;
+            }
         }
         /**
         * @description get the default value for TextArea field type
diff --git a/force-app/main/default/classes/TestDataFactory_Test.cls b/force-app/main/default/classes/TestDataFactory_Test.cls
index 78cec47..4ef5cbe 100644
--- a/force-app/main/default/classes/TestDataFactory_Test.cls
+++ b/force-app/main/default/classes/TestDataFactory_Test.cls
@@ -518,6 +518,8 @@ public class TestDataFactory_Test {
 			System.assertEquals('test',conList.get(0).Account.Name);
 		}catch(DmlException e) {
 			System.assert (true); // if missing required fields
+		}catch(TestDataFactory.TestDataFactoryException e) {
+			System.assert (true); // if missing required fields
 		}
 	}
 	/**
@@ -566,6 +568,8 @@ public class TestDataFactory_Test {
 			System.assertNotEquals(null,accList.get(0).Id);
 		}catch(DmlException e) {
 			System.assert (true); // if missing required fields
+		}catch(TestDataFactory.TestDataFactoryException e) {
+			System.assert (true); // if missing required fields
 		}
 	}
 
@@ -1011,7 +1015,8 @@ public class TestDataFactory_Test {
 		System.assertEquals(0,dvProvider.getDefaultValue(Lead.SObjectType.getDescribe(),Lead.fields.AnnualRevenue.getDescribe(),0)); // currency
 		System.assertEquals(Date.today(),dvProvider.getDefaultValue(Account.SObjectType.getDescribe(),Account.fields.LastActivityDate.getDescribe(),0)); // date
 		System.assertEquals(Datetime.now(),dvProvider.getDefaultValue(Account.SObjectType.getDescribe(),Account.fields.CreatedDate.getDescribe(),0)); // datetime
-		System.assertEquals('test0@email.com',dvProvider.getDefaultValue(Contact.SObjectType.getDescribe(),Contact.fields.Email.getDescribe(),0)); // email
+		System.assert(String.valueOf(dvProvider.getDefaultValue(Contact.SObjectType.getDescribe(),Contact.fields.Email.getDescribe(),0)).startsWith('test0')); // email
+		System.assert(String.valueOf(dvProvider.getDefaultValue(Contact.SObjectType.getDescribe(),Contact.fields.Email.getDescribe(),0)).endsWith('@email.com')); // email
 		// no standard geolocation field
 		System.assertEquals(0,dvProvider.getDefaultValue(Attachment.SObjectType.getDescribe(),Attachment.fields.BodyLength.getDescribe(),0)); // number
 		System.assertEquals(0,dvProvider.getDefaultValue(Asset.SObjectType.getDescribe(),Asset.fields.Quantity.getDescribe(),0)); // number
@@ -1022,7 +1027,7 @@ public class TestDataFactory_Test {
 		System.assertEquals('test0',dvProvider.getDefaultValue(Contact.SObjectType.getDescribe(),Contact.fields.FirstName.getDescribe(),0));  // text
 		System.assertEquals('test0',dvProvider.getDefaultValue(Account.SObjectType.getDescribe(),Account.fields.Description.getDescribe(),0)); // textarea
 		// no standard time field
-		System.assertEquals('http://test0.com',dvProvider.getDefaultValue(Account.SObjectType.getDescribe(),Account.fields.Website.getDescribe(),0));
+		System.assertEquals('http://test0.com',dvProvider.getDefaultValue(Account.SObjectType.getDescribe(),Account.fields.Website.getDescribe(),0)); // url
 		System.assertEquals(null,dvProvider.getDefaultValue(null,null,0));
 	}
 	@isTest
@@ -1033,7 +1038,8 @@ public class TestDataFactory_Test {
 		System.assertEquals(0,dvProvider.getCurrencyDefaultValue(null,null,0));
 		System.assertEquals(Date.today(),dvProvider.getDateDefaultValue(null,null,0));
 		System.assertEquals(Datetime.now(),dvProvider.getDateTimeDefaultValue(null,null,0));
-		System.assertEquals('test0@email.com',dvProvider.getEmailDefaultValue(null,null,0));
+		System.assert(String.valueOf(dvProvider.getEmailDefaultValue(null,null,0)).startsWith('test0'));
+		System.assert(String.valueOf(dvProvider.getEmailDefaultValue(null,null,0)).endsWith('@email.com'));
 		System.assertNotEquals(null,dvProvider.getGeolocationDefaultValue(null,null,0));
 		System.assertEquals(0,dvProvider.getNumberDefaultValue(null,null,0));
 		System.assertEquals(0,dvProvider.getPercentDefaultValue(null,null,0));
@@ -1076,7 +1082,8 @@ public class TestDataFactory_Test {
 		TestDataFactory.IFieldDefaultValue fieldDV8 = new TestDataFactory.FieldDefaultValue(new TestDataFactory.DefaultValueProvider(),Asset.SObjectType.getDescribe(),Asset.fields.Quantity.getDescribe());
 		System.assertEquals(0,fieldDV8.getValue(0));
 		TestDataFactory.IFieldDefaultValue fieldDV9 = new TestDataFactory.FieldDefaultValue(new TestDataFactory.DefaultValueProvider(),Contact.SObjectType.getDescribe(),Contact.fields.Email.getDescribe());
-		System.assertEquals('test0@email.com',fieldDV9.getValue(0));
+		System.assert(String.valueOf(fieldDV9.getValue(0)).startsWith('test0'));
+		System.assert(String.valueOf(fieldDV9.getValue(0)).endsWith('@email.com'));
 		TestDataFactory.IFieldDefaultValue fieldDV10 = new TestDataFactory.FieldDefaultValue(new TestDataFactory.DefaultValueProvider(),Account.SObjectType.getDescribe(),Account.fields.Id.getDescribe());
 		System.assertEquals(null,fieldDV10.getValue(0));
 		TestDataFactory.IFieldDefaultValue fieldDV11 = new TestDataFactory.FieldDefaultValue(new TestDataFactory.DefaultValueProvider(),Attachment.SObjectType.getDescribe(),Attachment.fields.BodyLength.getDescribe());