diff --git a/app/controllers/decidim/action_delegator/admin/delegations_controller.rb b/app/controllers/decidim/action_delegator/admin/delegations_controller.rb
index 04cd4184..e2902b83 100644
--- a/app/controllers/decidim/action_delegator/admin/delegations_controller.rb
+++ b/app/controllers/decidim/action_delegator/admin/delegations_controller.rb
@@ -25,7 +25,7 @@ def new
         def create
           enforce_permission_to :create, :delegation
 
-          @form = DelegationForm.from_params(params)
+          @form = form(DelegationForm).from_params(params)
 
           CreateDelegation.call(@form, current_user, current_setting) do
             on(:ok) do
diff --git a/app/forms/decidim/action_delegator/admin/delegation_form.rb b/app/forms/decidim/action_delegator/admin/delegation_form.rb
index 281a61bf..00488c01 100644
--- a/app/forms/decidim/action_delegator/admin/delegation_form.rb
+++ b/app/forms/decidim/action_delegator/admin/delegation_form.rb
@@ -18,15 +18,19 @@ class DelegationForm < Form
         validate :grantee_exists
 
         def granter
-          User.find_by(id: granter_id) || User.find_by(email: granter_email)
+          User.find_by(id: granter_id, organization: current_organization) || User.find_by(email: granter_email, organization: current_organization)
         end
 
         def grantee
-          User.find_by(id: grantee_id) || User.find_by(email: grantee_email)
+          User.find_by(id: grantee_id, organization: current_organization) || User.find_by(email: grantee_email, organization: current_organization)
         end
 
         private
 
+        def current_organization
+          context&.current_organization
+        end
+
         def granter_exists
           return if granter.present?
 
diff --git a/spec/commands/decidim/action_delegator/admin/create_delegation_spec.rb b/spec/commands/decidim/action_delegator/admin/create_delegation_spec.rb
index fcd73554..c6f060c9 100644
--- a/spec/commands/decidim/action_delegator/admin/create_delegation_spec.rb
+++ b/spec/commands/decidim/action_delegator/admin/create_delegation_spec.rb
@@ -69,4 +69,12 @@
       expect { subject.call }.to broadcast(:error)
     end
   end
+
+  context "when granter is not in the same organization" do
+    let(:granter) { create(:user) }
+
+    it "broadcasts :error" do
+      expect { subject.call }.to broadcast(:error)
+    end
+  end
 end
diff --git a/spec/forms/decidim/action_delegator/admin/delegation_form_spec.rb b/spec/forms/decidim/action_delegator/admin/delegation_form_spec.rb
index 0a18a52e..d2b92f0a 100644
--- a/spec/forms/decidim/action_delegator/admin/delegation_form_spec.rb
+++ b/spec/forms/decidim/action_delegator/admin/delegation_form_spec.rb
@@ -3,7 +3,7 @@
 require "spec_helper"
 
 describe Decidim::ActionDelegator::Admin::DelegationForm do
-  subject { described_class.from_params(attributes) }
+  subject { described_class.from_params(attributes).with_context(current_organization: organization) }
 
   let(:organization) { create(:organization) }
   let(:granter) { create(:user, organization: organization) }
@@ -23,6 +23,18 @@
 
   context "when there's granter and grantee" do
     it { is_expected.to be_valid }
+
+    context "when granter belongs to another organization" do
+      let(:granter) { create(:user) }
+
+      it { is_expected.not_to be_valid }
+    end
+
+    context "when grantee belongs to another organization" do
+      let(:grantee) { create(:user) }
+
+      it { is_expected.not_to be_valid }
+    end
   end
 
   context "when granter is missing" do
diff --git a/spec/models/decidim/action_delegator/delegation_spec.rb b/spec/models/decidim/action_delegator/delegation_spec.rb
index 97cd6fd6..3aebb8ba 100644
--- a/spec/models/decidim/action_delegator/delegation_spec.rb
+++ b/spec/models/decidim/action_delegator/delegation_spec.rb
@@ -11,6 +11,15 @@ module ActionDelegator
       it { is_expected.to be_valid }
       it { is_expected.not_to be_grantee_voted }
 
+      context "when grantee is the same as the granter" do
+        let(:setting) { create(:setting) }
+        let(:grantee) { create(:user, organization: setting.organization) }
+
+        subject { build(:delegation, setting: setting, grantee: grantee, granter: grantee) }
+
+        it { is_expected.not_to be_valid }
+      end
+
       context "when users from different organizations" do
         let(:grantee) { create(:user) }