diff --git a/Gemfile.lock b/Gemfile.lock
index 1ecfdd7..98f6e70 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -126,10 +126,10 @@ GEM
       ntlm-http (~> 0.1, >= 0.1.1)
       webrobots (~> 0.0, >= 0.0.9)
     meta_programming (0.2.2)
-    metaclass (0.0.1)
+    metaclass (0.0.4)
     method_source (0.8.1)
     mime-types (1.21)
-    mocha (0.10.0)
+    mocha (1.0.0)
       metaclass (~> 0.0.1)
     multi_json (1.6.0)
     mysql2 (0.3.11)
@@ -180,7 +180,7 @@ GEM
       rake (>= 0.8.7)
       rdoc (~> 3.4)
       thor (~> 0.14.6)
-    rake (10.0.3)
+    rake (10.1.1)
     rcov (0.9.10)
     rdoc (3.12.1)
       json (~> 1.4)
diff --git a/app/assets/javascripts/polls.coffee b/app/assets/javascripts/polls.coffee
index ba57fc8..2767447 100644
--- a/app/assets/javascripts/polls.coffee
+++ b/app/assets/javascripts/polls.coffee
@@ -19,6 +19,15 @@ $ ->
       $('#poll_form_url').focus()
     false
 
+  checkForceSubscription()
+  $('#poll_force_subscription_false').change checkForceSubscription
+  $('#poll_force_subscription_true').change checkForceSubscription
+
+checkForceSubscription = ->
+  readonly = $('#poll_force_subscription_true').is(':checked')
+  $('#poll_welcome_message').attr('readonly', readonly)
+  $('#poll_confirmation_word').attr('readonly', readonly)
+
 setupValidation = () ->
   jQuery.validator.addMethod(
     "hasChildren"
diff --git a/app/models/poll.rb b/app/models/poll.rb
index 67bb46d..aeaed99 100644
--- a/app/models/poll.rb
+++ b/app/models/poll.rb
@@ -1,17 +1,17 @@
 # Copyright (C) 2011-2012, InSTEDD
-# 
+#
 # This file is part of Pollit.
-# 
+#
 # Pollit is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
-# 
+#
 # Pollit 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 Pollit.  If not, see <http://www.gnu.org/licenses/>.
 
@@ -27,18 +27,18 @@ class Poll < ActiveRecord::Base
   validates :title, :presence => true, :length => {:maximum => 64}, :uniqueness => {:scope => :owner_id}
   validates :owner, :presence => true
   validates :form_url, :presence => true
-  validates :welcome_message, :presence => true, :length => {:maximum => 140}
+  validates :welcome_message, :presence => true, :length => {:maximum => 140}, :unless => :force_subscription
   validates :post_url, :presence => true
-  validates :confirmation_word, :presence => true
+  validates :confirmation_word, :presence => true, :unless => :force_subscription
   validates :goodbye_message, :presence => true, :length => {:maximum => 140}
   validates :questions, :presence => true
 
   accepts_nested_attributes_for :questions
-    
+
   after_initialize :default_values
 
   enum_attr :status, %w(^configuring started paused)
-  
+
   include Parser
   include AcceptAnswers
 
@@ -57,7 +57,7 @@ def start
     raise Exception.new("Cannot start poll #{self.id}") unless can_be_started?
 
     invite respondents
-    
+
     self.status = :started
     save
   end
@@ -78,13 +78,13 @@ def pause
 
   def resume
     raise Exception.new("Cannot resume unpaused poll #{self.id}") unless self.status_paused?
-    
+
     messages = []
-    
+
     # Invite respondents that were added while the poll was paused
     respondents_to_invite = self.respondents.where(:current_question_sent => false).where(:confirmed => false)
     invite respondents_to_invite
-    
+
     # Sends next questions to users with a current question and without the current_question_sent mark
     respondents_to_send_next_question = self.respondents.where(:current_question_sent => false).where('current_question_id IS NOT NULL')
     respondents_to_send_next_question.each do |r|
@@ -99,7 +99,7 @@ def resume
 
     send_messages messages
 
-    [respondents_to_send_next_question, respondents_to_goodbye].each do |rs| 
+    [respondents_to_send_next_question, respondents_to_goodbye].each do |rs|
       rs.update_all :current_question_sent => true
     end
 
@@ -140,28 +140,28 @@ def google_form_key
     query = URI.parse(form_url || post_url).query
     CGI::parse(query)['formkey'][0]
   end
-  
+
   def on_respondents_added
     invite_new_respondents if status_started?
   end
-  
+
   def invite_new_respondents
     respondents_to_invite = self.respondents.where(:current_question_sent => false).where(:confirmed => false)
     invite respondents_to_invite
   end
 
   private
-  
+
   def invite(respondents)
     messages = []
-    
+
     respondents.each do |respondent|
       messages << message_to(respondent, welcome_message)
     end
 
     # mark respondents as invited
     respondents.update_all :current_question_sent => true
-    
+
     send_messages messages
   end
 
diff --git a/app/views/polls/_form.haml b/app/views/polls/_form.haml
index 51beeae..da22d97 100644
--- a/app/views/polls/_form.haml
+++ b/app/views/polls/_form.haml
@@ -12,15 +12,18 @@
     .field
       = f.label :title
       = f.text_field :title, :class => 'required w60'
-    
+
     .field
       = f.label :description
       %p This is an internal description of the Poll, it will not be sent to your users
       = f.text_area :description, :class => 'w60', :rows => 5
 
-    
     .field
-      = f.label :welcome_message
+      = f.label :force_subscription, "#{f.radio_button(:force_subscription, true)} Force subscription".html_safe, value: true
+      %p Select this options <b>only</b> if you have explicit permission from the respondents to participate in your poll with their mobile phones.
+
+    .field
+      = f.label :force_subscription, "#{f.radio_button(:force_subscription, false)} Welcome message".html_safe, value: false
       %p This message will be sent to all respondents asking them if they agree to participate in the poll
       = f.text_area :welcome_message, :size => "28x5", :maxlength => 140, :class => 'required ux-wajbar w60', :readonly => !@poll.editable?
     .field
@@ -31,7 +34,7 @@
       = f.label :goodbye_message
       %p This message will be sent to respondents when they complete the poll
       = f.text_area :goodbye_message, :size => "28x5", :maxlength => 140, :class => 'ux-wajbar w60'
-    
+
     %hr
 
     = render :partial => 'form_questions', :locals => {f:f}
@@ -45,4 +48,4 @@
         = grey_button _("Next")
       - else
         = grey_button _("Save")
-        = white_link_to _("Cancel"), back_path
\ No newline at end of file
+        = white_link_to _("Cancel"), back_path
diff --git a/db/migrate/20140313123128_add_force_subscription_to_polls.rb b/db/migrate/20140313123128_add_force_subscription_to_polls.rb
new file mode 100644
index 0000000..30c75da
--- /dev/null
+++ b/db/migrate/20140313123128_add_force_subscription_to_polls.rb
@@ -0,0 +1,5 @@
+class AddForceSubscriptionToPolls < ActiveRecord::Migration
+  def change
+    add_column :polls, :force_subscription, :boolean, default: false
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index e46ac43..d579845 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20111213154341) do
+ActiveRecord::Schema.define(:version => 20140313123128) do
 
   create_table "answers", :force => true do |t|
     t.integer  "respondent_id"
@@ -37,11 +37,12 @@
     t.string   "form_url"
     t.datetime "created_at"
     t.datetime "updated_at"
-    t.string   "welcome_message",   :default => "YES"
+    t.string   "welcome_message",    :default => "YES"
     t.string   "status"
     t.string   "post_url"
     t.string   "confirmation_word"
     t.string   "goodbye_message"
+    t.boolean  "force_subscription", :default => false
   end
 
   create_table "questions", :force => true do |t|
diff --git a/spec/models/poll_spec.rb b/spec/models/poll_spec.rb
index 562c590..5446c13 100644
--- a/spec/models/poll_spec.rb
+++ b/spec/models/poll_spec.rb
@@ -1,18 +1,18 @@
 # encoding: UTF-8
 # Copyright (C) 2011-2012, InSTEDD
-# 
+#
 # This file is part of Pollit.
-# 
+#
 # Pollit is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
-# 
+#
 # Pollit 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 Pollit.  If not, see <http://www.gnu.org/licenses/>.
 
@@ -39,6 +39,22 @@
     it "must require questions if specified" do
       Poll.make_unsaved(:questions => []).should be_invalid
     end
+
+    it "must require welcome message" do
+      Poll.make_unsaved(welcome_message: nil).should be_invalid
+    end
+
+    it "must require confirmation word" do
+      Poll.make_unsaved(confirmation_word: nil).should be_invalid
+    end
+
+    it "can have welcome message empty if force subscription" do
+      Poll.make_unsaved(welcome_message: nil, force_subscription: true).should be_valid
+    end
+
+    it "can have confirmation word empty if force subscription" do
+      Poll.make_unsaved(confirmation_word: nil, force_subscription: true).should be_valid
+    end
   end
 
   context "parsing google form" do
@@ -375,4 +391,4 @@ def messages
     end
 
   end
-end
\ No newline at end of file
+end