diff --git a/back/app/jobs/automated_transition_job.rb b/back/app/jobs/automated_transition_job.rb
index 1d194c583a41..a6d33cc88cc4 100644
--- a/back/app/jobs/automated_transition_job.rb
+++ b/back/app/jobs/automated_transition_job.rb
@@ -4,6 +4,8 @@ class AutomatedTransitionJob < ApplicationJob
   queue_as :default
 
   def run
+    InputStatusService.auto_transition_hourly!
+
     return unless AppConfiguration.instance.feature_activated? 'initiatives'
 
     InitiativeStatusService.new.automated_transitions!
diff --git a/back/app/models/idea.rb b/back/app/models/idea.rb
index 280896f88877..052edeedfe55 100644
--- a/back/app/models/idea.rb
+++ b/back/app/models/idea.rb
@@ -183,9 +183,12 @@ def will_be_published?
     publication_status_change == %w[draft published] || publication_status_change == [nil, 'published']
   end
 
+  def consultation_context
+    creation_phase || project
+  end
+
   def custom_form
-    participation_context = creation_phase || project
-    participation_context.custom_form || CustomForm.new(participation_context: participation_context)
+    consultation_context.custom_form || CustomForm.new(participation_context: consultation_context)
   end
 
   def input_term
@@ -197,7 +200,7 @@ def input_term
   end
 
   def participation_method_on_creation
-    (creation_phase || project).pmethod
+    consultation_context.pmethod
   end
 
   private
diff --git a/back/app/services/input_status_service.rb b/back/app/services/input_status_service.rb
index cb66e698303e..d19db4b3aec8 100644
--- a/back/app/services/input_status_service.rb
+++ b/back/app/services/input_status_service.rb
@@ -1,12 +1,47 @@
 # frozen_string_literal: true
 
 class InputStatusService
+  AUTOMATED_TRANSITIONS = {
+    'proposed' => %w[threshold_reached expired]
+  }
+
   attr_reader :input_status
 
   def initialize(input_status)
     @input_status = input_status
   end
 
+  def self.auto_transition_input!(input)
+    AUTOMATED_TRANSITIONS[input.idea_status.code]&.each do |code_to|
+      can_transition = case code_to
+      when 'threshold_reached'
+        threshold_reached_condition?(input)
+      else
+        false
+      end
+
+      apply_transition!(input, code_to) if can_transition
+    end
+  end
+
+  def self.auto_transition_hourly!
+    AUTOMATED_TRANSITIONS&.each do |code_from, codes_to|
+      inputs = Idea.includes(:idea_status).where(idea_status: { code: code_from })
+      codes_to.each do |code_to|
+        inputs_to_transition = case code_to
+        when 'expired'
+          expired_scope(inputs)
+        else
+          inputs.none
+        end
+
+        inputs_to_transition.each do |input|
+          apply_transition!(input, code_to)
+        end
+      end
+    end
+  end
+
   def can_transition_manually?
     case input_status.participation_method
     when 'ideation'
@@ -21,4 +56,33 @@ def can_transition_manually?
   def can_reorder?
     !input_status.automatic?
   end
+
+  private
+
+  private_class_method def self.apply_transition!(input, code_to)
+    code_from = input.idea_status.code
+    status_to = IdeaStatus.find_by(code: code_to, participation_method: input.participation_method_on_creation.class.method_str)
+    input.update!(idea_status: status_to)
+    LogActivityJob.perform_later(
+      input,
+      'changed_input_status',
+      nil,
+      Time.zone.now.to_i,
+      payload: { input_status_from_code: code_from, input_status_to_code: code_to }
+    )
+  end
+
+  private_class_method def self.threshold_reached_condition?(input)
+    threshold = input.consultation_context.try(:reacting_threshold)
+    threshold && input.likes_count >= threshold
+  end
+
+  private_class_method def self.expired_scope(inputs, now = Time.zone.now)
+    # This code assumes that the consultation context corresponds to
+    # the creation phase, which is not yet the case for ideation.
+    inputs
+      .includes(:creation_phase)
+      .where.not(creation_phase: { expire_days_limit: nil })
+      .where("published_at + creation_phase.expire_days_limit * interval '1 day' < ?", now)
+  end
 end
diff --git a/back/app/services/side_fx_reaction_service.rb b/back/app/services/side_fx_reaction_service.rb
index f5693c388de1..6a3b4c916435 100644
--- a/back/app/services/side_fx_reaction_service.rb
+++ b/back/app/services/side_fx_reaction_service.rb
@@ -4,6 +4,8 @@ class SideFxReactionService
   include SideFxHelper
 
   def after_create(reaction, current_user)
+    InputStatusService.auto_transition_input!(reaction.reactable.reload) if reaction.reactable_type == 'Idea'
+
     if reaction.reactable_type == 'Initiative'
       AutomatedTransitionJob.perform_now
 
diff --git a/back/spec/acceptance/idea_reactions_spec.rb b/back/spec/acceptance/idea_reactions_spec.rb
index 1ee6b8e7712b..c305c812963d 100644
--- a/back/spec/acceptance/idea_reactions_spec.rb
+++ b/back/spec/acceptance/idea_reactions_spec.rb
@@ -76,6 +76,21 @@
         assert_status 422
       end
     end
+
+    describe do
+      let!(:status_threshold_reached) { create(:proposals_status, code: 'threshold_reached') }
+      let(:phase) { create(:proposals_phase, reacting_threshold: 2) }
+      let(:proposal) { create(:proposal, idea_status: create(:proposals_status, code: 'proposed'), creation_phase: phase, project: phase.project, phases: [phase]) }
+      let(:idea_id) { proposal.id }
+
+      example 'Reaching the voting threshold immediately triggers status change', document: false do
+        create_list(:reaction, 2, reactable: proposal, mode: 'up')
+
+        do_request
+        assert_status 201
+        expect(proposal.reload.idea_status).to eq status_threshold_reached
+      end
+    end
   end
 
   post 'web_api/v1/ideas/:idea_id/reactions/up' do
diff --git a/back/spec/acceptance/initiative_reactions_spec.rb b/back/spec/acceptance/initiative_reactions_spec.rb
index 931d43cefd03..22a9efb62ebe 100644
--- a/back/spec/acceptance/initiative_reactions_spec.rb
+++ b/back/spec/acceptance/initiative_reactions_spec.rb
@@ -68,6 +68,7 @@
       expect(@initiative.reload.likes_count).to eq 3
     end
 
+    # TODO: cleanup-after-proposals-migration
     example 'Reaching the voting threshold immediately triggers status change', document: false do
       settings = AppConfiguration.instance.settings
       settings['initiatives']['reacting_threshold'] = 3
diff --git a/back/spec/acceptance/initiatives_spec.rb b/back/spec/acceptance/initiatives_spec.rb
index 53e9aa7b2fed..a10de82653b4 100644
--- a/back/spec/acceptance/initiatives_spec.rb
+++ b/back/spec/acceptance/initiatives_spec.rb
@@ -759,7 +759,7 @@
     end
   end
 
-  # TODO: move-old-proposals-test
+  # TODO: cleanup-after-proposals-migration
   get 'web_api/v1/initiatives/:id/allowed_transitions' do
     before do
       admin_header_token
diff --git a/back/spec/factories/phases.rb b/back/spec/factories/phases.rb
index 20d07366d052..c767cde3a2bf 100644
--- a/back/spec/factories/phases.rb
+++ b/back/spec/factories/phases.rb
@@ -65,6 +65,8 @@
 
     factory :proposals_phase do
       participation_method { 'proposals' }
+      start_at { Time.zone.today - 7.days }
+      end_at { Time.zone.today + 7.days }
     end
 
     factory :poll_phase do
diff --git a/back/spec/services/initiative_status_service_spec.rb b/back/spec/services/initiative_status_service_spec.rb
index a05837e9c89a..bfc0b4c74519 100644
--- a/back/spec/services/initiative_status_service_spec.rb
+++ b/back/spec/services/initiative_status_service_spec.rb
@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-# TODO: move-old-proposals-test
+# TODO: cleanup-after-proposals-migration
 describe InitiativeStatusService do
   let(:service) { described_class.new }
 
diff --git a/back/spec/services/input_status_service_spec.rb b/back/spec/services/input_status_service_spec.rb
new file mode 100644
index 000000000000..cd772c8f8779
--- /dev/null
+++ b/back/spec/services/input_status_service_spec.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe InputStatusService do
+  describe 'automated transitions' do
+    before do
+      %w[proposed threshold_reached expired].each do |status_code|
+        create(:proposals_status, code: status_code)
+      end
+    end
+
+    let(:phase) { create(:proposals_phase, reacting_threshold: 2, expire_days_limit: 20) }
+    let!(:proposal) { create(:proposal, idea_status: IdeaStatus.find_by(code: 'proposed'), creation_phase: phase, project: phase.project, phases: [phase], published_at: Time.now) }
+
+    describe 'auto_transition_input!' do
+      it 'transitions when voting threshold was reached' do
+        create_list(:reaction, 3, reactable: proposal, mode: 'up')
+
+        described_class.auto_transition_input!(proposal.reload)
+
+        expect(proposal.reload.idea_status.code).to eq 'threshold_reached'
+      end
+
+      it 'remains proposed if not expired nor threshold reached' do
+        create(:reaction, reactable: proposal, mode: 'up')
+
+        travel_to(Time.now + 15.days) do
+          described_class.auto_transition_input!(proposal.reload)
+          expect(proposal.reload.idea_status.code).to eq 'proposed'
+        end
+      end
+    end
+
+    describe 'auto_transition_hourly!' do
+      it 'transitions when expired' do
+        create(:idea)
+        travel_to(Time.now + 22.days) do
+          described_class.auto_transition_hourly!
+          expect(proposal.reload.idea_status.code).to eq 'expired'
+        end
+      end
+
+      it 'remains proposed if not expired nor threshold reached' do
+        create(:reaction, reactable: proposal, mode: 'up')
+
+        travel_to(Time.now + 19.days) do
+          described_class.auto_transition_hourly!
+          expect(proposal.reload.idea_status.code).to eq 'proposed'
+        end
+      end
+    end
+  end
+end