diff --git a/app/controllers/account_controller.rb b/app/controllers/account_controller.rb
index 091a280e6..23af8c91b 100644
--- a/app/controllers/account_controller.rb
+++ b/app/controllers/account_controller.rb
@@ -26,7 +26,7 @@ class AccountController < ApplicationController
       if @account.organization?
         params.require(:account).permit(:phone_number, :email_on_debate_comment, :email_on_comment_reply, organization_attributes: [:name])
       else
-        params.require(:account).permit(:first_name, :last_name, :phone_number, :nickname, :use_nickname, :email_on_debate_comment, :email_on_comment_reply)
+        params.require(:account).permit(:username, :email_on_debate_comment, :email_on_comment_reply)
       end
     end
 
diff --git a/app/controllers/users/registrations_controller.rb b/app/controllers/users/registrations_controller.rb
index 65da7e1e0..0ef0ba638 100644
--- a/app/controllers/users/registrations_controller.rb
+++ b/app/controllers/users/registrations_controller.rb
@@ -12,7 +12,7 @@ class Users::RegistrationsController < Devise::RegistrationsController
   private
 
     def sign_up_params
-      params.require(:user).permit(:first_name, :last_name, :email, :phone_number, :password, :password_confirmation, :use_nickname, :nickname, :captcha, :captcha_key)
+      params.require(:user).permit(:username, :email, :password, :password_confirmation, :captcha, :captcha_key)
     end
 
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index 52287d9f4..4a93f8cf1 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -11,9 +11,7 @@ class User < ActiveRecord::Base
   has_one :moderator
   has_one :organization
 
-  validates :first_name, presence: true, if: :use_first_name?
-  validates :last_name,  presence: true, if: :use_last_name?
-  validates :nickname,   presence: true, if: :use_nickname?
+  validates :username,   presence: true, unless: :organization?
   validates :official_level, inclusion: {in: 0..5}
 
   validates_associated :organization, message: false
@@ -27,9 +25,7 @@ class User < ActiveRecord::Base
   scope :officials,      -> { where("official_level > 0") }
 
   def name
-    return nickname          if use_nickname?
-    return organization.name if organization?
-    "#{first_name} #{last_name}"
+    organization? ? organization.name : username
   end
 
   def debate_votes(debates)
@@ -70,12 +66,4 @@ class User < ActiveRecord::Base
     e.present? ? where(email: e) : none
   end
 
-  private
-    def use_first_name?
-      !organization? && !use_nickname?
-    end
-
-    def use_last_name?
-      use_first_name?
-    end
 end
diff --git a/app/views/account/show.html.erb b/app/views/account/show.html.erb
index fb647ef1d..d24343ea5 100644
--- a/app/views/account/show.html.erb
+++ b/app/views/account/show.html.erb
@@ -16,19 +16,12 @@
             <%= f.fields_for :organization do |fo| %>
               <%= fo.text_field :name, autofocus: true, placeholder: t("account.show.organization_name_label") %>
             <% end %>
+            <%= f.text_field :phone_number, placeholder: t("account.show.phone_number_label") %>
 
           <% else %>
-
-            <%= f.text_field :first_name, placeholder: t("account.show.first_name_label") %>
-            <%= f.text_field :last_name, placeholder:  t("account.show.last_name_label") %>
-            <%= f.text_field :nickname, placeholder: t("account.show.nickname_label") %>
-
-            <%= f.check_box :use_nickname, label: false %>
-            <span class="checkbox"><%= t("account.show.use_nickname_label") %></span>
-
+            <%= f.text_field :username, placeholder: t("account.show.username_label") %>
           <% end %>
 
-          <%= f.text_field :phone_number, placeholder: t("account.show.phone_number_label") %>
         </div>
 
         <div class="small-12 medium-6 column">
diff --git a/app/views/users/registrations/new.html.erb b/app/views/users/registrations/new.html.erb
index c39c5f5f1..418dddfef 100644
--- a/app/views/users/registrations/new.html.erb
+++ b/app/views/users/registrations/new.html.erb
@@ -6,15 +6,8 @@
         <%= render 'shared/errors', resource: resource %>
         <div class="row">
           <div class="small-12 column">
-            <%= f.text_field :first_name, autofocus: true,
-                             placeholder: t("devise_views.users.registrations.new.first_name_label") %>
-            <%= f.text_field  :last_name, placeholder: t("devise_views.users.registrations.new.last_name_label") %>
+            <%= f.text_field  :username,  placeholder: t("devise_views.users.registrations.new.username_label") %>
             <%= f.email_field :email,     placeholder: t("devise_views.users.registrations.new.email_label") %>
-            <%= f.text_field  :nickname,  placeholder: t("devise_views.users.registrations.new.nickname_label") %>
-
-            <%= f.check_box :use_nickname, label: t("devise_views.users.registrations.new.use_nickname_label") %>
-
-            <%= f.text_field  :phone_number,  placeholder: t("devise_views.users.registrations.new.phone_number_label") %>
 
             <%= f.password_field :password, autocomplete: "off",
                                  placeholder: t("devise_views.users.registrations.new.password_label") %>
diff --git a/config/locales/activerecord.en.yml b/config/locales/activerecord.en.yml
index 8a4063d9a..94b1fa0c9 100644
--- a/config/locales/activerecord.en.yml
+++ b/config/locales/activerecord.en.yml
@@ -18,9 +18,7 @@ en:
         title: Title
       user:
         email: Email
-        first_name: "First name"
-        last_name: "Last name"
-        nickname: Nickname
+        username: Username
         password: Password
         phone_number: Phone number
         official_position: Official position
diff --git a/config/locales/activerecord.es.yml b/config/locales/activerecord.es.yml
index b5fa8050e..f566026de 100644
--- a/config/locales/activerecord.es.yml
+++ b/config/locales/activerecord.es.yml
@@ -18,9 +18,7 @@ es:
         title: Título
       user:
         email: Correo electrónico
-        first_name: Nombre
-        last_name: Apellidos
-        nickname: Pseudónimo
+        username: Nombre de usuario
         password: Contraseña
         phone_number: Teléfono
         official_position: Cargo público
diff --git a/config/locales/devise_views.en.yml b/config/locales/devise_views.en.yml
index e5a1ec48d..c782806ec 100644
--- a/config/locales/devise_views.en.yml
+++ b/config/locales/devise_views.en.yml
@@ -50,12 +50,8 @@ en:
           back_link: "Back"
         new:
           title: "Sign up"
-          first_name_label: "First name"
-          last_name_label: "Last name"
-          nickname_label: "Nickname"
-          use_nickname_label: "Use nickname"
+          username_label: "Username to use publicly"
           email_label: "Email"
-          phone_number_label: "Phone number"
           password_label: "Password"
           password_confirmation_label: "Confirm password"
           submit: "Sign up"
diff --git a/config/locales/devise_views.es.yml b/config/locales/devise_views.es.yml
index c44ddfb31..18754529b 100644
--- a/config/locales/devise_views.es.yml
+++ b/config/locales/devise_views.es.yml
@@ -50,12 +50,8 @@ es:
           back_link: "Atrás"
         new:
           title: "Registrarse"
-          first_name_label: "Nombre"
-          last_name_label: "Apellidos"
-          nickname_label: "Pseudónimo"
-          use_nickname_label: "Usar pseudónimo"
+          username_label: "Nombre a utilizar públicamente"
           email_label: "Email"
-          phone_number_label: "Teléfono"
           password_label: "Contraseña"
           password_confirmation_label: "Confirmar contraseña"
           submit: "Registrarse"
diff --git a/config/locales/en.yml b/config/locales/en.yml
index a2ea265f3..1366b3e4b 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -120,12 +120,9 @@ en:
       change_credentials_link: "Change my credentials"
       avatar: "Avatar"
       personal: "Personal data"
-      first_name_label: "First Name"
-      last_name_label: "Last Name"
+      username_label: "Username"
       phone_number_label: "Phone number"
       organization_name_label: "Organization name"
-      use_nickname_label: "Use nickname"
-      nickname_label: "Nickname"
       notifications: Notifications
   simple_captcha:
     placeholder: "Enter the image value"
diff --git a/config/locales/es.yml b/config/locales/es.yml
index 8d24181c4..e4a6a873c 100644
--- a/config/locales/es.yml
+++ b/config/locales/es.yml
@@ -120,12 +120,9 @@ es:
       email_on_comment_reply_label: "Recibir un email cuando alguien contesta a mis comentarios"
       avatar: "Avatar"
       personal: "Datos personales"
-      first_name_label: "Nombre"
-      last_name_label: "Apellidos"
+      username_label: "Nombre de usuario"
       phone_number_label: "Teléfono"
       organization_name_label: "Nombre de la organización"
-      use_nickname_label: "Usar pseudónimo"
-      nickname_label: "Pseudónimo"
       notifications: Notificaciones
   simple_captcha:
     placeholder: "Introduce el texto de la imagen"
diff --git a/db/migrate/20150821130019_changes_user_registrations_fields.rb b/db/migrate/20150821130019_changes_user_registrations_fields.rb
new file mode 100644
index 000000000..600762324
--- /dev/null
+++ b/db/migrate/20150821130019_changes_user_registrations_fields.rb
@@ -0,0 +1,10 @@
+class ChangesUserRegistrationsFields < ActiveRecord::Migration
+  def change
+    add_column :users, :username, :string
+
+    remove_column :users, :first_name, :string
+    remove_column :users, :last_name, :string
+    remove_column :users, :nickname, :string
+    remove_column :users, :use_nickname, :boolean, default: false, null: false
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 6d3005fbf..3cd1b55d1 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: 20150819135933) do
+ActiveRecord::Schema.define(version: 20150821130019) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -130,20 +130,17 @@ ActiveRecord::Schema.define(version: 20150819135933) do
     t.string   "last_sign_in_ip"
     t.datetime "created_at",                                         null: false
     t.datetime "updated_at",                                         null: false
-    t.string   "first_name"
-    t.string   "last_name"
     t.string   "confirmation_token"
     t.datetime "confirmed_at"
     t.datetime "confirmation_sent_at"
     t.string   "unconfirmed_email"
-    t.string   "nickname"
-    t.boolean  "use_nickname",                       default: false, null: false
     t.boolean  "email_on_debate_comment",            default: false
     t.boolean  "email_on_comment_reply",             default: false
     t.string   "official_position"
     t.integer  "official_level",                     default: 0
-    t.string   "phone_number",            limit: 30
     t.datetime "hidden_at"
+    t.string   "phone_number",            limit: 30
+    t.string   "username"
   end
 
   add_index "users", ["confirmation_token"], name: "index_users_on_confirmation_token", unique: true, using: :btree
diff --git a/spec/factories.rb b/spec/factories.rb
index a6090efbb..101ce2746 100644
--- a/spec/factories.rb
+++ b/spec/factories.rb
@@ -1,8 +1,7 @@
 FactoryGirl.define do
 
   factory :user do
-    first_name       'Manuela'
-    last_name        'Carmena'
+    username         'Manuela'
     sequence(:email) { |n| "manuela#{n}@madrid.es" }
     password         'judgmentday'
     confirmed_at     { Time.now }
diff --git a/spec/features/account_spec.rb b/spec/features/account_spec.rb
index 28785ed08..93cfe3dd0 100644
--- a/spec/features/account_spec.rb
+++ b/spec/features/account_spec.rb
@@ -3,7 +3,7 @@ require 'rails_helper'
 feature 'Account' do
 
   background do
-    @user = create(:user, first_name: "Manuela", last_name: "Colau")
+    @user = create(:user, username: "Manuela Colau")
     login_as(@user)
   end
 
@@ -14,8 +14,7 @@ feature 'Account' do
 
     expect(current_path).to eq(account_path)
 
-    expect(page).to have_selector("input[value='Manuela']")
-    expect(page).to have_selector("input[value='Colau']")
+    expect(page).to have_selector("input[value='Manuela Colau']")
     expect(page).to have_selector(avatar('Manuela Colau'), count: 1)
   end
 
@@ -25,8 +24,7 @@ feature 'Account' do
     visit account_path
 
     expect(page).to have_selector("input[value='Manuela Corp']")
-    expect(page).to_not have_selector("input[value='Manuela']")
-    expect(page).to_not have_selector("input[value='Colau']")
+    expect(page).to_not have_selector("input[value='Manuela Colau']")
 
     expect(page).to have_selector(avatar('Manuela Corp'), count: 1)
   end
@@ -34,8 +32,7 @@ feature 'Account' do
   scenario 'Edit' do
     visit account_path
 
-    fill_in 'account_first_name', with: 'Larry'
-    fill_in 'account_last_name', with: 'Bird'
+    fill_in 'account_username', with: 'Larry Bird'
     check 'account_email_on_debate_comment'
     check 'account_email_on_comment_reply'
     click_button 'Save changes'
@@ -44,8 +41,7 @@ feature 'Account' do
 
     visit account_path
 
-    expect(page).to have_selector("input[value='Larry']")
-    expect(page).to have_selector("input[value='Bird']")
+    expect(page).to have_selector("input[value='Larry Bird']")
     expect(page).to have_selector("input[id='account_email_on_debate_comment'][value='1']")
     expect(page).to have_selector("input[id='account_email_on_comment_reply'][value='1']")
   end
@@ -71,7 +67,7 @@ feature 'Account' do
   scenario "Errors on edit" do
     visit account_path
 
-    fill_in 'account_first_name', with: ''
+    fill_in 'account_username', with: ''
     click_button 'Save changes'
 
     expect(page).to have_content error_message
diff --git a/spec/features/admin/officials_spec.rb b/spec/features/admin/officials_spec.rb
index 6824ccf62..90cd88501 100644
--- a/spec/features/admin/officials_spec.rb
+++ b/spec/features/admin/officials_spec.rb
@@ -3,7 +3,7 @@ require 'rails_helper'
 feature 'Admin officials' do
 
   background do
-    @citizen = create(:user, first_name: "Citizen", last_name: "Kane")
+    @citizen = create(:user, username: "Citizen Kane")
     @official = create(:user, official_position: "Mayor", official_level: 5)
     @admin = create(:administrator)
     login_as(@admin.user)
diff --git a/spec/features/comments_spec.rb b/spec/features/comments_spec.rb
index b820fffcd..f7738464a 100644
--- a/spec/features/comments_spec.rb
+++ b/spec/features/comments_spec.rb
@@ -80,8 +80,8 @@ feature 'Comments' do
   end
 
   scenario 'Reply', :js do
-    citizen = create(:user, first_name: 'Ana')
-    manuela = create(:user, first_name: 'Manuela')
+    citizen = create(:user, username: 'Ana')
+    manuela = create(:user, username: 'Manuela')
     debate  = create(:debate)
     comment = create(:comment, commentable: debate, user: citizen)
 
diff --git a/spec/features/users_spec.rb b/spec/features/users_spec.rb
index 2b7984833..42511f28c 100644
--- a/spec/features/users_spec.rb
+++ b/spec/features/users_spec.rb
@@ -6,8 +6,7 @@ feature 'Users' do
     visit '/'
     click_link 'Sign up'
 
-    fill_in 'user_first_name',            with: 'Manuela'
-    fill_in 'user_last_name',             with: 'Carmena'
+    fill_in 'user_username',              with: 'Manuela Carmena'
     fill_in 'user_email',                 with: 'manuela@madrid.es'
     fill_in 'user_password',              with: 'judgementday'
     fill_in 'user_password_confirmation', with: 'judgementday'
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index f64888236..5a4bbdf88 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -30,6 +30,12 @@ describe User do
     expect(subject).to be_valid
   end
 
+  describe "#name" do
+    it "is the username when the user is not an organization" do
+      expect(subject.name).to eq(subject.username)
+    end
+  end
+
   describe 'preferences' do
     describe 'email_on_debate_comment' do
       it 'should be false by default' do
@@ -44,45 +50,6 @@ describe User do
     end
   end
 
-  describe 'use_nickname' do
-    describe 'when true' do
-      before { subject.use_nickname = true }
-
-      it "activates the validation of nickname" do
-        subject.nickname = nil
-        expect(subject).to_not be_valid
-
-        subject.nickname = "dredd"
-        expect(subject).to be_valid
-      end
-
-      it "calculates the name using the nickname" do
-        subject.nickname = "dredd"
-        expect(subject.name).to eq("dredd")
-      end
-    end
-
-    describe 'when false' do
-      before { subject.use_nickname = false }
-
-      it "activates the validation of first_name and last_name" do
-        subject.first_name = nil
-        subject.last_name = nil
-        expect(subject).to_not be_valid
-
-        subject.first_name = "Joseph"
-        subject.last_name = "Dredd"
-        expect(subject).to be_valid
-      end
-
-      it "calculates the name using first_name and last_name" do
-        subject.first_name = "Joseph"
-        subject.last_name = "Dredd"
-        expect(subject.name).to eq("Joseph Dredd")
-      end
-    end
-  end
-
   describe "administrator?" do
     it "is false when the user is not an admin" do
       expect(subject.administrator?).to be false
@@ -152,9 +119,8 @@ describe User do
       expect(subject.organization.name).to eq('org')
     end
 
-    it "deactivates the validation of first_name and last_name, and activates the validation of organization" do
-      subject.first_name = nil
-      subject.last_name = nil
+    it "deactivates the validation of username, and activates the validation of organization" do
+      subject.username = nil
       expect(subject).to be_valid
 
       subject.organization.name= nil
diff --git a/spec/support/common_actions.rb b/spec/support/common_actions.rb
index 32252aa1a..21a98f56f 100644
--- a/spec/support/common_actions.rb
+++ b/spec/support/common_actions.rb
@@ -4,8 +4,7 @@ module CommonActions
     visit '/'
     click_link 'Sign up'
 
-    fill_in 'user_first_name',            with: 'Manuela'
-    fill_in 'user_last_name',             with: 'Carmena'
+    fill_in 'user_username',              with: 'Manuela Carmena'
     fill_in 'user_email',                 with: 'manuela@madrid.es'
     fill_in 'user_password',              with: 'judgementday'
     fill_in 'user_password_confirmation', with: 'judgementday'