diff --git a/app/models/identity.rb b/app/models/identity.rb
new file mode 100644
index 000000000..e0778dfae
--- /dev/null
+++ b/app/models/identity.rb
@@ -0,0 +1,10 @@
+class Identity < ActiveRecord::Base
+  belongs_to :user
+
+  validates :provider, presence: true
+  validates :uid, presence: true, uniqueness: { scope: :provider }
+
+  def self.find_for_oauth(auth)
+    where(uid: auth.uid, provider: auth.provider).first_or_create
+  end
+end
diff --git a/db/migrate/20150824144524_create_identities.rb b/db/migrate/20150824144524_create_identities.rb
new file mode 100644
index 000000000..38a5e603a
--- /dev/null
+++ b/db/migrate/20150824144524_create_identities.rb
@@ -0,0 +1,11 @@
+class CreateIdentities < ActiveRecord::Migration
+  def change
+    create_table :identities do |t|
+      t.references :user, index: true, foreign_key: true
+      t.string :provider
+      t.string :uid
+
+      t.timestamps null: false
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 12e457a1c..d21459719 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20150824113326) do
+ActiveRecord::Schema.define(version: 20150824144524) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -66,8 +66,8 @@ ActiveRecord::Schema.define(version: 20150824113326) do
     t.integer  "author_id"
     t.datetime "created_at",                                        null: false
     t.datetime "updated_at",                                        null: false
-    t.datetime "hidden_at"
     t.string   "visit_id"
+    t.datetime "hidden_at"
     t.datetime "flagged_as_inappropiate_at"
     t.integer  "inappropiate_flags_count",              default: 0
     t.datetime "reviewed_at"
@@ -75,6 +75,16 @@ ActiveRecord::Schema.define(version: 20150824113326) do
 
   add_index "debates", ["hidden_at"], name: "index_debates_on_hidden_at", using: :btree
 
+  create_table "identities", force: :cascade do |t|
+    t.integer  "user_id"
+    t.string   "provider"
+    t.string   "uid"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
+  add_index "identities", ["user_id"], name: "index_identities_on_user_id", using: :btree
+
   create_table "inappropiate_flags", force: :cascade do |t|
     t.integer  "user_id"
     t.string   "flaggable_type"
@@ -156,10 +166,10 @@ ActiveRecord::Schema.define(version: 20150824113326) do
     t.string   "unconfirmed_email"
     t.boolean  "email_on_debate_comment",            default: false
     t.boolean  "email_on_comment_reply",             default: false
+    t.string   "phone_number",            limit: 30
     t.string   "official_position"
     t.integer  "official_level",                     default: 0
     t.datetime "hidden_at"
-    t.string   "phone_number",            limit: 30
     t.string   "username"
   end
 
@@ -214,6 +224,7 @@ ActiveRecord::Schema.define(version: 20150824113326) do
   add_index "votes", ["voter_id", "voter_type", "vote_scope"], name: "index_votes_on_voter_id_and_voter_type_and_vote_scope", using: :btree
 
   add_foreign_key "administrators", "users"
+  add_foreign_key "identities", "users"
   add_foreign_key "inappropiate_flags", "users"
   add_foreign_key "moderators", "users"
   add_foreign_key "organizations", "users"
diff --git a/spec/factories.rb b/spec/factories.rb
index 038a0102e..4fa2a70e3 100644
--- a/spec/factories.rb
+++ b/spec/factories.rb
@@ -1,5 +1,4 @@
 FactoryGirl.define do
-
   factory :user do
     username         'Manuela'
     sequence(:email) { |n| "manuela#{n}@madrid.es" }
@@ -7,6 +6,12 @@ FactoryGirl.define do
     confirmed_at     { Time.now }
   end
 
+  factory :identity do
+    user nil
+    provider "Twitter"
+    uid "MyString"
+  end
+
   factory :debate do
     sequence(:title)     { |n| "Debate #{n} title" }
     description          'Debate description'
diff --git a/spec/models/identity_spec.rb b/spec/models/identity_spec.rb
new file mode 100644
index 000000000..82d5c4be3
--- /dev/null
+++ b/spec/models/identity_spec.rb
@@ -0,0 +1,9 @@
+require 'rails_helper'
+
+RSpec.describe Identity, type: :model do
+  let(:identity) { build(:identity) }
+
+  it "should be valid" do
+    expect(identity).to be_valid
+  end
+end
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 5a4bbdf88..e0260285a 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -50,6 +50,26 @@ describe User do
     end
   end
 
+  describe 'OmniAuth' do
+    describe '#email_provided?' do
+      it "is false if the email matchs was temporarely assigned by the OmniAuth process" do
+        subject.email = 'omniauth@participacion-ABCD-twitter.com'
+        expect(subject.email_provided?).to eq(false)
+      end
+
+      it "is true if the email is not omniauth-like" do
+        subject.email = 'manuelacarmena@example.com'
+        expect(subject.email_provided?).to eq(true)
+      end
+
+      it "is true if the user's real email is pending to be confirmed" do
+        subject.email = 'omniauth@participacion-ABCD-twitter.com'
+        subject.unconfirmed_email = 'manuelacarmena@example.com'
+        expect(subject.email_provided?).to eq(true)
+      end
+    end
+  end
+
   describe "administrator?" do
     it "is false when the user is not an admin" do
       expect(subject.administrator?).to be false