diff --git a/app/controllers/organisation_relationships_controller.rb b/app/controllers/organisation_relationships_controller.rb
index 65617baac..0ac66bd31 100644
--- a/app/controllers/organisation_relationships_controller.rb
+++ b/app/controllers/organisation_relationships_controller.rb
@@ -33,14 +33,17 @@ class OrganisationRelationshipsController < ApplicationController
 
   def add_stock_owner
     @organisation_relationship = organisation.parent_organisation_relationships.new
+    authorize @organisation_relationship
   end
 
   def add_managing_agent
     @organisation_relationship = organisation.child_organisation_relationships.new
+    authorize @organisation_relationship
   end
 
   def create_stock_owner
     @organisation_relationship = organisation.parent_organisation_relationships.new(organisation_relationship_params)
+    authorize @organisation_relationship
     if @organisation_relationship.save(context: :stock_owner)
       flash[:notice] = "#{@organisation_relationship.parent_organisation.name} is now one of #{current_user.data_coordinator? ? 'your' : "this organisation's"} stock owners"
       redirect_to stock_owners_organisation_path
@@ -52,6 +55,7 @@ class OrganisationRelationshipsController < ApplicationController
 
   def create_managing_agent
     @organisation_relationship = organisation.child_organisation_relationships.new(organisation_relationship_params)
+    authorize @organisation_relationship
     if @organisation_relationship.save
       flash[:notice] = "#{@organisation_relationship.child_organisation.name} is now one of #{current_user.data_coordinator? ? 'your' : "this organisation's"} managing agents"
       redirect_to managing_agents_organisation_path
@@ -61,7 +65,13 @@ class OrganisationRelationshipsController < ApplicationController
     end
   end
 
-  def remove_stock_owner; end
+  def remove_stock_owner
+    organisation_relationship = OrganisationRelationship.find_by!(
+      parent_organisation: @target_organisation,
+      child_organisation: organisation,
+    )
+    authorize organisation_relationship
+  end
 
   def delete_stock_owner
     OrganisationRelationship.find_by!(
@@ -72,7 +82,13 @@ class OrganisationRelationshipsController < ApplicationController
     redirect_to stock_owners_organisation_path
   end
 
-  def remove_managing_agent; end
+  def remove_managing_agent
+    organisation_relationship = OrganisationRelationship.find_by!(
+      parent_organisation: organisation,
+      child_organisation: @target_organisation,
+    )
+    authorize organisation_relationship
+  end
 
   def delete_managing_agent
     OrganisationRelationship.find_by!(
diff --git a/app/policies/organisation_relationship_policy.rb b/app/policies/organisation_relationship_policy.rb
new file mode 100644
index 000000000..4b748f597
--- /dev/null
+++ b/app/policies/organisation_relationship_policy.rb
@@ -0,0 +1,21 @@
+class OrganisationRelationshipPolicy
+  attr_reader :user, :organisation_relationship
+
+  def initialize(user, organisation_relationship)
+    @user = user
+    @organisation_relationship = organisation_relationship
+  end
+
+  %w[
+    add_stock_owner?
+    create_stock_owner?
+    remove_stock_owner?
+    add_managing_agent?
+    create_managing_agent?
+    remove_managing_agent?
+  ].each do |method_name|
+    define_method method_name do
+      !user.data_provider?
+    end
+  end
+end
diff --git a/spec/requests/organisation_relationships_controller_spec.rb b/spec/requests/organisation_relationships_controller_spec.rb
index 83af2b981..78b894b7f 100644
--- a/spec/requests/organisation_relationships_controller_spec.rb
+++ b/spec/requests/organisation_relationships_controller_spec.rb
@@ -296,6 +296,94 @@ RSpec.describe OrganisationRelationshipsController, type: :request do
         end
       end
 
+      context "when directly accessing the page to add a stock owner" do
+        let(:request) { get "/organisations/#{organisation.id}/stock-owners/add" }
+
+        it "returns 401" do
+          request
+          expect(response).to have_http_status(:unauthorized)
+        end
+      end
+
+      context "when directly adding a stock owner" do
+        let!(:stock_owner) { FactoryBot.create(:organisation) }
+        let(:params) do
+          {
+            "organisation_relationship": {
+              "parent_organisation_id": stock_owner.id,
+            },
+          }
+        end
+        let(:request) { post "/organisations/#{organisation.id}/stock-owners", params: }
+
+        it "returns 401" do
+          request
+          expect(response).to have_http_status(:unauthorized)
+        end
+
+        it "does not create a new organisation relationship" do
+          expect { request }.not_to change(OrganisationRelationship, :count)
+        end
+      end
+
+      context "when directly removing a stock owner" do
+        let(:stock_owner) { FactoryBot.create(:organisation) }
+        let(:request) { get "/organisations/#{organisation.id}/stock-owners/remove?target_organisation_id=#{stock_owner.id}" }
+
+        before do
+          FactoryBot.create(:organisation_relationship, parent_organisation: stock_owner, child_organisation: organisation)
+        end
+
+        it "returns 401" do
+          request
+          expect(response).to have_http_status(:unauthorized)
+        end
+      end
+
+      context "when directly accessing the page to add a managing agent" do
+        let(:request) { get "/organisations/#{organisation.id}/managing-agents/add" }
+
+        it "returns 401" do
+          request
+          expect(response).to have_http_status(:unauthorized)
+        end
+      end
+
+      context "when directly adding a managing agent" do
+        let!(:managing_agent) { FactoryBot.create(:organisation) }
+        let(:params) do
+          {
+            "organisation_relationship": {
+              "child_organisation_id": managing_agent.id,
+            },
+          }
+        end
+        let(:request) { post "/organisations/#{organisation.id}/managing-agents", params: }
+
+        it "returns 401" do
+          request
+          expect(response).to have_http_status(:unauthorized)
+        end
+
+        it "does not create a new organisation relationship" do
+          expect { request }.not_to change(OrganisationRelationship, :count)
+        end
+      end
+
+      context "when directly removing a managing agent" do
+        let(:managing_agent) { FactoryBot.create(:organisation) }
+        let(:request) { get "/organisations/#{organisation.id}/managing-agents/remove?target_organisation_id=#{managing_agent.id}" }
+
+        before do
+          FactoryBot.create(:organisation_relationship, parent_organisation: organisation, child_organisation: managing_agent)
+        end
+
+        it "returns 401" do
+          request
+          expect(response).to have_http_status(:unauthorized)
+        end
+      end
+
       context "when accessing the managing agents tab" do
         context "with an organisation that the user belongs to" do
           let!(:managing_agent) { FactoryBot.create(:organisation) }
@@ -333,16 +421,6 @@ RSpec.describe OrganisationRelationshipsController, type: :request do
           end
         end
 
-        context "when adding a managing agent" do
-          before do
-            get "/organisations/#{organisation.id}/managing-agents/add", headers:, params: {}
-          end
-
-          it "has the correct header" do
-            expect(response.body).to include("What is the name of your managing agent?")
-          end
-        end
-
         context "with an organisation that are not in scope for the user, i.e. that they do not belong to" do
           before do
             get "/organisations/#{unauthorised_organisation.id}/managing-agents", headers:, params: {}