diff --git a/app/controllers/organisations_controller.rb b/app/controllers/organisations_controller.rb
index dfe50fa22..9d3e63b33 100644
--- a/app/controllers/organisations_controller.rb
+++ b/app/controllers/organisations_controller.rb
@@ -4,8 +4,8 @@ class OrganisationsController < ApplicationController
   include DuplicateLogsHelper
 
   before_action :authenticate_user!
-  before_action :find_resource, except: %i[index new create]
-  before_action :authenticate_scope!, except: [:index]
+  before_action :find_resource, except: %i[index new create search]
+  before_action :authenticate_scope!, except: %i[index search]
   before_action :session_filters, if: -> { current_user.support? || current_user.organisation.has_managing_agents? }, only: %i[lettings_logs sales_logs email_lettings_csv download_lettings_csv email_sales_csv download_sales_csv]
   before_action :session_filters, only: %i[users schemes email_schemes_csv download_schemes_csv]
   before_action -> { filter_manager.serialize_filters_to_session }, if: -> { current_user.support? || current_user.organisation.has_managing_agents? }, only: %i[lettings_logs sales_logs email_lettings_csv download_lettings_csv email_sales_csv download_sales_csv]
@@ -280,6 +280,17 @@ class OrganisationsController < ApplicationController
     render "schemes/changes"
   end
 
+  def search
+    org_options = current_user.support? ? Organisation.all : Organisation.affiliated_organisations(current_user.organisation)
+    organisations = org_options.search_by(params["query"]).limit(20)
+
+    org_data = organisations.each_with_object({}) do |org, hash|
+      hash[org.id] = { value: org.name }
+    end
+
+    render json: org_data.to_json
+  end
+
 private
 
   def filter_type
diff --git a/app/frontend/controllers/search_controller.js b/app/frontend/controllers/search_controller.js
index 6d447f7f8..ada55d820 100644
--- a/app/frontend/controllers/search_controller.js
+++ b/app/frontend/controllers/search_controller.js
@@ -11,8 +11,8 @@ const populateOptions = (results, selectEl) => {
     const option = document.createElement('option')
     option.value = key
     option.innerHTML = searchableName(results[key])
-    option.setAttribute('data-hint', results[key].hint)
-    option.textContent = searchableName(results[key])
+    if (results[key].hint) { option.setAttribute('data-hint', results[key].hint) }
+    option.setAttribute('text', searchableName(results[key]))
     selectEl.appendChild(option)
     options.push(option)
   })
@@ -23,14 +23,14 @@ export default class extends Controller {
     const selectEl = this.element
     const matches = /^(\w+)\[(\w+)\]$/.exec(selectEl.name)
     const rawFieldName = matches ? `${matches[1]}[${matches[2]}_raw]` : ''
-    const relativeUrlRoute = JSON.parse(this.element.dataset.info).relative_url_route
+    const searchUrl = JSON.parse(this.element.dataset.info).search_url
 
     accessibleAutocomplete.enhanceSelectElement({
       defaultValue: '',
       selectElement: selectEl,
       minLength: 1,
       source: (query, populateResults) => {
-        fetchAndPopulateSearchResults(query, populateResults, relativeUrlRoute, populateOptions, selectEl)
+        fetchAndPopulateSearchResults(query, populateResults, searchUrl, populateOptions, selectEl)
       },
       autoselect: true,
       placeholder: 'Start typing to search',
diff --git a/app/frontend/modules/search.js b/app/frontend/modules/search.js
index b232c2a08..c2679b80c 100644
--- a/app/frontend/modules/search.js
+++ b/app/frontend/modules/search.js
@@ -119,8 +119,9 @@ export const suggestion = (value, options) => {
 
 export const searchSuggestion = (value, options) => {
   try {
-    const result = enhanceOption(options.find((o) => o.innerHTML === value))
-    if (result) {
+    const option = options.find((o) => o.innerHTML === value)
+    if (option) {
+      const result = enhanceOption(option)
       const html = result.append ? `<span class="autocomplete__option__append">${result.text}</span> <span>${result.append}</span>` : `<span>${result.text}</span>`
       return result.hint ? `${html}<div class="autocomplete__option__hint">${result.hint}</div>` : html
     } else {
@@ -151,14 +152,9 @@ export const fetchAndPopulateSearchResults = async (query, populateResults, rela
   }
 }
 
-export const fetchUserOptions = async (query, relativeUrlRoute) => {
+export const fetchUserOptions = async (query, searchUrl) => {
   try {
-    let response
-    if (relativeUrlRoute) {
-      response = await fetch(`${relativeUrlRoute}/users/search?query=${encodeURIComponent(query)}`)
-    } else {
-      response = await fetch(`/users/search?query=${encodeURIComponent(query)}`)
-    }
+    const response = await fetch(`${searchUrl}?query=${encodeURIComponent(query)}`)
     const results = await response.json()
     return results
   } catch (error) {
@@ -172,7 +168,7 @@ export const getSearchableName = (option) => {
 }
 
 export const searchableName = (option) => {
-  return option.value + ' ' + option.hint
+  return option.hint ? option.value + ' ' + option.hint : option.value
 }
 
 export const confirmSelectedOption = (selectEl, val) => {
diff --git a/app/helpers/filters_helper.rb b/app/helpers/filters_helper.rb
index 12845fce4..81a986ebf 100644
--- a/app/helpers/filters_helper.rb
+++ b/app/helpers/filters_helper.rb
@@ -84,13 +84,31 @@ module FiltersHelper
     JSON.parse(session[session_name_for(filter_type)])[filter] || ""
   end
 
-  def owning_organisation_filter_options(user)
-    organisation_options = user.support? ? Organisation.all : ([user.organisation] + user.organisation.stock_owners + user.organisation.absorbed_organisations).uniq
-    [OpenStruct.new(id: "", name: "Select an option")] + organisation_options.map { |org| OpenStruct.new(id: org.id, name: org.name) }
+  def owning_organisation_filter_options(_user, filter_type)
+    if applied_filters(filter_type)["owning_organisation"].present?
+      org = Organisation.find(applied_filters(filter_type)["owning_organisation"]) # make sure this doesn't expose anything weird
+      [OpenStruct.new(id: org.id, name: org.name)]
+    else
+      [OpenStruct.new(id: "", name: "Select an option")]
+    end
   end
 
-  def assigned_to_filter_options
-    [OpenStruct.new(id: "", name: "Select an option", hint: "")]
+  def assigned_to_filter_options(filter_type)
+    if applied_filters(filter_type)["assigned_to"] == "specific_user"
+      user = User.find(applied_filters(filter_type)["user"]) # make sure this doesn't expose anything weird
+      [OpenStruct.new(id: user.id, name: user.name, hint: user.email)]
+    else
+      [OpenStruct.new(id: "", name: "Select an option", hint: "")]
+    end
+  end
+
+  def filter_search_url(category)
+    case category
+    when :user
+      ENV["RAILS_RELATIVE_URL_ROOT"].present? ? "#{ENV['RAILS_RELATIVE_URL_ROOT']}/users/search" : "/users/search"
+    when :owning_organisation, :managing_organisation
+      ENV["RAILS_RELATIVE_URL_ROOT"].present? ? "#{ENV['RAILS_RELATIVE_URL_ROOT']}/organisations/search" : "/organisations/search"
+    end
   end
 
   def collection_year_options
@@ -124,9 +142,13 @@ module FiltersHelper
     end
   end
 
-  def managing_organisation_filter_options(user)
-    organisation_options = user.support? ? Organisation.all : ([user.organisation] + user.organisation.managing_agents + user.organisation.absorbed_organisations).uniq
-    [OpenStruct.new(id: "", name: "Select an option")] + organisation_options.map { |org| OpenStruct.new(id: org.id, name: org.name) }
+  def managing_organisation_filter_options(_user, filter_type)
+    if applied_filters(filter_type)["managing_organisation"].present?
+      org = Organisation.find(applied_filters(filter_type)["managing_organisation"]) # make sure this doesn't expose anything weird
+      [OpenStruct.new(id: org.id, name: org.name)]
+    else
+      [OpenStruct.new(id: "", name: "Select an option")]
+    end
   end
 
   def show_scheme_managing_org_filter?(user)
diff --git a/app/models/organisation.rb b/app/models/organisation.rb
index 8f77df166..f0e8ca243 100644
--- a/app/models/organisation.rb
+++ b/app/models/organisation.rb
@@ -18,6 +18,7 @@ class Organisation < ApplicationRecord
   belongs_to :absorbing_organisation, class_name: "Organisation", optional: true
   has_many :absorbed_organisations, class_name: "Organisation", foreign_key: "absorbing_organisation_id"
   scope :visible, -> { where(discarded_at: nil) }
+  scope :affiliated_organisations, ->(organisation) { where(id: (organisation.child_organisations + [organisation] + organisation.parent_organisations).map(&:id)) }
 
   def affiliated_stock_owners
     ids = []
diff --git a/app/views/filters/_select_filter.html.erb b/app/views/filters/_select_filter.html.erb
index 70d7e007d..9e564bfb2 100644
--- a/app/views/filters/_select_filter.html.erb
+++ b/app/views/filters/_select_filter.html.erb
@@ -1,7 +1,7 @@
 <%= f.govuk_select(category.to_sym,
   label: { text: label, hidden: secondary },
   "data-controller": "search conditional-filter",
-  "data-info": {relative_url_route: ENV["RAILS_RELATIVE_URL_ROOT"]}.to_json) do %>
+  "data-info": { search_url: filter_search_url(category.to_sym) }.to_json) do %>
     <% collection.each do |answer| %>
       <option value="<%= answer.id %>"
         data-hint="<%= answer.hint %>"
diff --git a/app/views/filters/managed_by.html.erb b/app/views/filters/managed_by.html.erb
index e3d849c9b..df3c04af7 100644
--- a/app/views/filters/managed_by.html.erb
+++ b/app/views/filters/managed_by.html.erb
@@ -9,7 +9,7 @@
           type: "select",
           label: "Managed by",
           category: "managing_organisation",
-          options: managing_organisation_filter_options(current_user),
+          options: managing_organisation_filter_options(current_user, @filter_type),
         },
       },
     },
diff --git a/app/views/filters/owned_by.html.erb b/app/views/filters/owned_by.html.erb
index 7acfd459c..43b61ec73 100644
--- a/app/views/filters/owned_by.html.erb
+++ b/app/views/filters/owned_by.html.erb
@@ -9,7 +9,7 @@
           type: "select",
           label: "Owning Organisation",
           category: "owning_organisation",
-          options: owning_organisation_filter_options(current_user),
+          options: owning_organisation_filter_options(current_user, @filter_type),
         },
       },
     },
diff --git a/app/views/logs/_log_filters.html.erb b/app/views/logs/_log_filters.html.erb
index 2a209b8fe..fed0643d0 100644
--- a/app/views/logs/_log_filters.html.erb
+++ b/app/views/logs/_log_filters.html.erb
@@ -69,7 +69,7 @@
                            type: "select",
                            label: "User",
                            category: "user",
-                           options: assigned_to_filter_options,
+                           options: assigned_to_filter_options(@filter_type),
                          },
                        },
                      },
@@ -89,7 +89,7 @@
                   type: "select",
                   label: "Owning Organisation",
                   category: "owning_organisation",
-                  options: owning_organisation_filter_options(current_user),
+                  options: owning_organisation_filter_options(current_user, @filter_type),
                 },
               },
             },
@@ -110,7 +110,7 @@
                   type: "select",
                   label: user_or_org_lettings_path? ? "Managed by" : "Reported by",
                   category: "managing_organisation",
-                  options: managing_organisation_filter_options(current_user),
+                  options: managing_organisation_filter_options(current_user, @filter_type),
                 },
               },
             },
diff --git a/config/routes.rb b/config/routes.rb
index 1d0a58e67..faea457fe 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -195,6 +195,10 @@ Rails.application.routes.draw do
       get "delete-confirmation", to: "organisations#delete_confirmation"
       delete "delete", to: "organisations#delete"
     end
+
+    collection do
+      get :search
+    end
   end
 
   resources :merge_requests, path: "/merge-request" do
diff --git a/spec/requests/organisations_controller_spec.rb b/spec/requests/organisations_controller_spec.rb
index 13879a38c..d3e8a8155 100644
--- a/spec/requests/organisations_controller_spec.rb
+++ b/spec/requests/organisations_controller_spec.rb
@@ -75,6 +75,13 @@ RSpec.describe OrganisationsController, type: :request do
         end
       end
     end
+
+    describe "#search" do
+      it "redirects to the sign in page" do
+        get "/organisations/search"
+        expect(response).to redirect_to("/account/sign-in")
+      end
+    end
   end
 
   context "when user is signed in" do
@@ -807,6 +814,25 @@ RSpec.describe OrganisationsController, type: :request do
           end
         end
       end
+
+      describe "#search" do
+        let(:parent_organisation) { create(:organisation, name: "parent test organisation") }
+        let(:child_organisation) { create(:organisation, name: "child test organisation") }
+
+        before do
+          user.organisation.update!(name: "test organisation")
+          create(:organisation_relationship, parent_organisation: user.organisation, child_organisation:)
+          create(:organisation_relationship, child_organisation: user.organisation, parent_organisation:)
+          create(:organisation, name: "other organisation test organisation")
+        end
+
+        it "only searches within the current user's organisation, managing agents and stock owners" do
+          get "/organisations/search", headers:, params: { query: "test organisation" }
+          result = JSON.parse(response.body)
+          expect(result.count).to eq(3)
+          expect(result.keys).to match_array([user.organisation.id.to_s, parent_organisation.id.to_s, child_organisation.id.to_s])
+        end
+      end
     end
 
     context "with a data provider user" do
@@ -2077,6 +2103,25 @@ RSpec.describe OrganisationsController, type: :request do
           end
         end
       end
+
+      describe "#search" do
+        let(:parent_organisation) { create(:organisation, name: "parent test organisation") }
+        let(:child_organisation) { create(:organisation, name: "child test organisation") }
+        let!(:other_organisation) { create(:organisation, name: "other organisation test organisation") }
+
+        before do
+          user.organisation.update!(name: "test organisation")
+          create(:organisation_relationship, parent_organisation: user.organisation, child_organisation:)
+          create(:organisation_relationship, child_organisation: user.organisation, parent_organisation:)
+        end
+
+        it "searches within all the organisations" do
+          get "/organisations/search", headers:, params: { query: "test organisation" }
+          result = JSON.parse(response.body)
+          expect(result.count).to eq(4)
+          expect(result.keys).to match_array([user.organisation.id.to_s, parent_organisation.id.to_s, child_organisation.id.to_s, other_organisation.id.to_s])
+        end
+      end
     end
   end