diff --git a/app/controllers/new_administrateur/services_controller.rb b/app/controllers/new_administrateur/services_controller.rb
index 4e1538fad..9e5d682a4 100644
--- a/app/controllers/new_administrateur/services_controller.rb
+++ b/app/controllers/new_administrateur/services_controller.rb
@@ -70,7 +70,7 @@ module NewAdministrateur
     private
 
     def service_params
-      params.require(:service).permit(:nom, :organisme, :type_organisme, :email, :telephone, :horaires, :adresse)
+      params.require(:service).permit(:nom, :organisme, :siret, :type_organisme, :email, :telephone, :horaires, :adresse)
     end
 
     def service
diff --git a/app/models/service.rb b/app/models/service.rb
index 2521a4f04..363190aa8 100644
--- a/app/models/service.rb
+++ b/app/models/service.rb
@@ -18,6 +18,7 @@ class Service < ApplicationRecord
   validates :nom, presence: { message: 'doit être renseigné' }, allow_nil: false
   validates :nom, uniqueness: { scope: :administrateur, message: 'existe déjà' }
   validates :organisme, presence: { message: 'doit être renseigné' }, allow_nil: false
+  validates :siret, length: { is: 14, message: 'doit être une suite de 14 chiffres' }, allow_nil: true
   validates :type_organisme, presence: { message: 'doit être renseigné' }, allow_nil: false
   validates :email, presence: { message: 'doit être renseigné' }, allow_nil: false
   validates :telephone, presence: { message: 'doit être renseigné' }, allow_nil: false
diff --git a/app/views/new_administrateur/services/_form.html.haml b/app/views/new_administrateur/services/_form.html.haml
index 80f50a57e..0fb2e0a3b 100644
--- a/app/views/new_administrateur/services/_form.html.haml
+++ b/app/views/new_administrateur/services/_form.html.haml
@@ -10,6 +10,16 @@
     %span.mandatory *
   = f.text_field :organisme, placeholder: "mairie de Mours, préfecture de l'Oise, ministère de la Culture", required: true
 
+  = f.label :siret do
+    SIRET
+    %span.mandatory *
+  %p
+    Pour trouver votre numéro SIRET, utilisez
+    %a{ href: 'https://entreprise.data.gouv.fr/', target: '_blank' }
+      entreprise.data.gouv.fr
+    ou renseignez-vous auprès de votre service comptable
+  = f.number_field :siret, required: true
+
   = f.label :type_organisme do
     Type d’organisme
     %span.mandatory *
diff --git a/db/migrate/20180719125038_add_siret_to_services.rb b/db/migrate/20180719125038_add_siret_to_services.rb
new file mode 100644
index 000000000..275be8b54
--- /dev/null
+++ b/db/migrate/20180719125038_add_siret_to_services.rb
@@ -0,0 +1,5 @@
+class AddSiretToServices < ActiveRecord::Migration[5.2]
+  def change
+    add_column :services, :siret, :string
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 0dc4b2cc9..d756990b4 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2018_06_27_092237) do
+ActiveRecord::Schema.define(version: 2018_07_19_125038) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -541,6 +541,7 @@ ActiveRecord::Schema.define(version: 2018_06_27_092237) do
     t.string "telephone"
     t.text "horaires"
     t.text "adresse"
+    t.string "siret"
     t.index ["administrateur_id", "nom"], name: "index_services_on_administrateur_id_and_nom", unique: true
     t.index ["administrateur_id"], name: "index_services_on_administrateur_id"
   end
diff --git a/spec/controllers/new_administrateur/services_controller_spec.rb b/spec/controllers/new_administrateur/services_controller_spec.rb
index c3fb96838..8bf213f79 100644
--- a/spec/controllers/new_administrateur/services_controller_spec.rb
+++ b/spec/controllers/new_administrateur/services_controller_spec.rb
@@ -13,6 +13,7 @@ describe NewAdministrateur::ServicesController, type: :controller do
           service: {
             nom: 'super service',
             organisme: 'organisme',
+            siret: '01234567891234',
             type_organisme: 'region',
             email: 'email@toto.com',
             telephone: '1234',
@@ -27,6 +28,7 @@ describe NewAdministrateur::ServicesController, type: :controller do
       it { expect(flash.notice).to eq('super service créé') }
       it { expect(Service.last.nom).to eq('super service') }
       it { expect(Service.last.organisme).to eq('organisme') }
+      it { expect(Service.last.siret).to eq('01234567891234') }
       it { expect(Service.last.type_organisme).to eq('region') }
       it { expect(Service.last.email).to eq('email@toto.com') }
       it { expect(Service.last.telephone).to eq('1234') }