diff --git a/app/models/enterprise.rb b/app/models/enterprise.rb
index b4dc488..fa2bc6b 100644
--- a/app/models/enterprise.rb
+++ b/app/models/enterprise.rb
@@ -1,3 +1,5 @@
 #A enterprise is a kind of profile. According to the system concept, only enterprises can offer priducts/services
 class Enterprise < Profile
+
+  validates_numericality_of :foundation_year, :only_integer => true
 end
diff --git a/test/unit/enterprise_test.rb b/test/unit/enterprise_test.rb
index cc4b7db..ddb80ba 100644
--- a/test/unit/enterprise_test.rb
+++ b/test/unit/enterprise_test.rb
@@ -1,10 +1,65 @@
 require File.dirname(__FILE__) + '/../test_helper'
 
 class EnterpriseTest < Test::Unit::TestCase
-  fixtures :profiles
+  fixtures :profiles, :virtual_communities, :users
 
-  # Replace this with your real tests.
-  def test_truth
-    assert true
+  def test_identifier_validation
+    p = Enterprise.new
+    p.valid?
+    assert p.errors.invalid?(:identifier)
+
+    p.identifier = 'with space'
+    p.valid?
+    assert p.errors.invalid?(:identifier)
+
+    p.identifier = 'áéíóú'
+    p.valid?
+    assert p.errors.invalid?(:identifier)
+
+    p.identifier = 'rightformat2007'
+    p.valid?
+    assert ! p.errors.invalid?(:identifier)
+
+    p.identifier = 'rightformat'
+    p.valid?
+    assert ! p.errors.invalid?(:identifier)
+
+    p.identifier = 'right_format'
+    p.valid?
+    assert ! p.errors.invalid?(:identifier)
+  end
+
+  def test_has_domains
+    p = Enterprise.new
+    assert_kind_of Array, p.domains
+  end
+
+  def test_belongs_to_virtual_community_and_has_default
+    p = Enterprise.new
+    assert_kind_of VirtualCommunity, p.virtual_community
   end
+
+  def test_cannot_rename
+    p1 = profiles(:johndoe)
+    assert_raise ArgumentError do
+      p1.identifier = 'bli'
+    end
+  end
+
+  def test_numericality_year
+    count = Enterprise.count
+
+    e = Enterprise.new(:identifier => 'test_numericality_year')
+    e.foundation_year = 'xxxx'
+    assert ! e.save
+
+    e.foundation_year = 20.07
+    assert ! e.save
+
+    e.foundation_year = 2007
+    assert e.save
+
+    assert count + 1, Enterprise.count
+  end
+
 end
--
libgit2 0.21.2