diff --git a/.rubocop.yml b/.rubocop.yml
index 2b259040..22fc107a 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -86,6 +86,7 @@ Layout/LineLength:
     Exclude:
         - 'lib/tasks/yarn.rake'
         - 'spec/support/api_helpers.rb'
+        - 'app/controllers/user_details_controller.rb'
 
 Metrics/BlockLength:
     Max: 40
diff --git a/app/assets/stylesheets/components/button/_button.scss b/app/assets/stylesheets/components/button/_button.scss
index 1c08b9b4..0538f9a0 100644
--- a/app/assets/stylesheets/components/button/_button.scss
+++ b/app/assets/stylesheets/components/button/_button.scss
@@ -37,4 +37,8 @@ $button-shadow-size: $govuk-border-width-form-element;
 .govuk-back-link {
   background-color: transparent;
   border: none;
+}
+
+.button-group {
+  align-items: normal;
 }
\ No newline at end of file
diff --git a/app/controllers/user_details_controller.rb b/app/controllers/user_details_controller.rb
index dc7ee1fe..d707b9c6 100644
--- a/app/controllers/user_details_controller.rb
+++ b/app/controllers/user_details_controller.rb
@@ -49,6 +49,32 @@ def update_email
     render :edit_email, status: :service_unavailable
   end
 
+  def deactivate_confirmation
+    return if current_user.can_deactivate?
+
+    redirect_to user_detail_path,
+                alert: 'You cannot deactivate your account because you are the only active user for a linked supplier.'
+  end
+
+  def deactivate
+    unless current_user.can_deactivate?
+      return redirect_to user_detail_path,
+                         alert: 'You cannot deactivate your account because you are the only active user for a linked supplier.'
+    end
+
+    API::User.deactivate
+
+    reset_session
+
+    redirect_to root_path, notice: 'Your account has been deactivated.'
+  rescue JSONAPI::Consumer::Errors::UnprocessableEntity
+    redirect_to user_detail_path,
+                alert: 'You can no longer deactivate your account because you are the only active user for a linked supplier.'
+  rescue JSONAPI::Consumer::Errors::ConnectionError
+    redirect_to deactivate_confirmation_user_detail_path,
+                alert: 'There was a problem connecting to the user service. Please try again later.'
+  end
+
   private
 
   def email_update_validation(email, confirmation)
diff --git a/app/models/api/user.rb b/app/models/api/user.rb
index 984def89..6cb86013 100644
--- a/app/models/api/user.rb
+++ b/app/models/api/user.rb
@@ -2,6 +2,7 @@ module API
   class User < Base
     custom_endpoint :update_name, on: :collection, request_method: :patch
     custom_endpoint :update_email, on: :collection, request_method: :patch
+    custom_endpoint :deactivate, on: :collection, request_method: :patch
     custom_endpoint :user_auth_logs, on: :collection, request_method: :get
   end
 end
diff --git a/app/views/user_details/deactivate_confirmation.html.haml b/app/views/user_details/deactivate_confirmation.html.haml
new file mode 100644
index 00000000..25073c95
--- /dev/null
+++ b/app/views/user_details/deactivate_confirmation.html.haml
@@ -0,0 +1,27 @@
+- page_title 'Deactivate my account'
+
+= link_to 'Back', user_detail_path, { class: 'govuk-back-link', title: 'Back to user profile page' }
+
+.govuk-grid-row
+  .govuk-grid-column-three-quarters
+    %h1.govuk-heading-xl
+      Deactivate my account
+    
+    %p
+      By choosing to proceed you will be logged out of the Report-MI service and will no longer be able 
+      to log in using this account. Management information tasks you have previously completed on behalf 
+      of your organisation(s) are preserved and your account access can be restored in the future by 
+      contacting support: 
+      = mail_to(support_email_address)
+
+    .govuk-button-group{ class: 'button-group govuk-!-margin-top-7' }
+      = button_to 'Continue to deactivate my account',
+                  deactivate_user_detail_path,
+                  method: :patch,
+                  class: 'govuk-button',
+                  data: { module: 'govuk-button' }
+
+      = link_to 'Cancel',
+                user_detail_path,
+                class: 'govuk-button'
+      
\ No newline at end of file
diff --git a/app/views/user_details/show.html.haml b/app/views/user_details/show.html.haml
index 081cd35e..4230b760 100644
--- a/app/views/user_details/show.html.haml
+++ b/app/views/user_details/show.html.haml
@@ -38,6 +38,8 @@
           %td.govuk-table__cell User since
           %td.govuk-table__cell= user_created_date(current_user).to_fs(:default)
           %td.govuk-table__cell
+            - if current_user.can_deactivate?
+              = link_to 'Deactivate account', deactivate_confirmation_user_detail_path, class: 'govuk-link'
         - if @user_logs.present?
           %tr.govuk-table__row
             %td.govuk-table__cell Previous logins
diff --git a/config/routes.rb b/config/routes.rb
index cbedcae9..df3d51b1 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -44,6 +44,8 @@
   resource :user_detail, only: %i[show edit update] do
     get :edit_email
     patch :update_email
+    get :deactivate_confirmation, path: 'deactivate'
+    patch :deactivate
   end
 
   match '/auth/:provider/callback', to: 'sessions#create', via: %i[get post]
diff --git a/spec/features/user_can_deactivate_account_spec.rb b/spec/features/user_can_deactivate_account_spec.rb
new file mode 100644
index 00000000..1e3d6190
--- /dev/null
+++ b/spec/features/user_can_deactivate_account_spec.rb
@@ -0,0 +1,30 @@
+require 'rails_helper'
+
+RSpec.describe 'deactivating an account' do
+  before do
+    mock_sso_with(email: 'email@example.com')
+    mock_notifications_endpoint!
+    mock_user_who_can_deactivate_endpoint!
+    mock_suppliers_endpoint!
+    mock_email_verification_pending_endpoint!
+    mock_user_auth_logs_endpoint!
+    mock_deactivate_user_endpoint!
+  end
+
+  scenario 'an eligible user deactivates their account' do
+    visit '/'
+    click_button 'sign-in'
+    visit user_detail_path
+
+    click_link 'Deactivate account'
+
+    expect(page).to have_content 'Deactivate my account'
+    expect(page).to have_link('Back', href: user_detail_path)
+    expect(page).to have_link('Cancel', href: user_detail_path)
+
+    click_button 'Continue to deactivate my account'
+
+    expect(page).to have_current_path(root_path)
+    expect(page).to have_content 'Your account has been deactivated.'
+  end
+end
diff --git a/spec/fixtures/mocks/user_deactivated.json b/spec/fixtures/mocks/user_deactivated.json
new file mode 100644
index 00000000..3fa20277
--- /dev/null
+++ b/spec/fixtures/mocks/user_deactivated.json
@@ -0,0 +1,16 @@
+{
+    "data": {
+        "id": "111c2bdd-4090-466b-8dec-66cdf0fc4871",
+        "type": "users",
+        "attributes": {
+            "multiple_suppliers?": false,
+            "can_deactivate?": true,
+            "name": "User Name",
+            "email": "user@example.com",
+            "created_at": "2025-12-09T15:25:43.025Z"
+        }
+    },
+    "jsonapi": {
+        "version": "1.0"
+    }
+}
\ No newline at end of file
diff --git a/spec/fixtures/mocks/user_who_can_deactivate.json b/spec/fixtures/mocks/user_who_can_deactivate.json
new file mode 100644
index 00000000..29f9949f
--- /dev/null
+++ b/spec/fixtures/mocks/user_who_can_deactivate.json
@@ -0,0 +1,18 @@
+{
+  "data": [
+    {
+      "id": "efa8ebb8-de51-4718-b085-a583f8d41e3f",
+      "type": "users",
+      "attributes": {
+        "multiple_suppliers?": false,
+        "can_deactivate?": true,
+        "name": "User Name",
+        "email": "user@example.com",
+        "created_at": "2023-10-01T12:00:00Z"
+      }
+    }
+  ],
+  "jsonapi": {
+    "version": "1.0"
+  }
+}
diff --git a/spec/fixtures/mocks/user_who_cannot_deactivate.json b/spec/fixtures/mocks/user_who_cannot_deactivate.json
new file mode 100644
index 00000000..8b28bb98
--- /dev/null
+++ b/spec/fixtures/mocks/user_who_cannot_deactivate.json
@@ -0,0 +1,18 @@
+{
+  "data": [
+    {
+      "id": "efa8ebb8-de51-4718-b085-a583f8d41e3f",
+      "type": "users",
+      "attributes": {
+        "multiple_suppliers?": false,
+        "can_deactivate?": false,
+        "name": "User Name",
+        "email": "user@example.com",
+        "created_at": "2023-10-01T12:00:00Z"
+      }
+    }
+  ],
+  "jsonapi": {
+    "version": "1.0"
+  }
+}
diff --git a/spec/fixtures/mocks/user_with_multiple_suppliers.json b/spec/fixtures/mocks/user_with_multiple_suppliers.json
index c85ac44d..88afca7a 100644
--- a/spec/fixtures/mocks/user_with_multiple_suppliers.json
+++ b/spec/fixtures/mocks/user_with_multiple_suppliers.json
@@ -5,6 +5,7 @@
       "type": "users",
       "attributes": {
         "multiple_suppliers?": true,
+        "can_deactivate?": true,
         "name": "User Name",
         "email": "user@example.com",
         "created_at": "2023-10-01T12:00:00Z"
diff --git a/spec/requests/user_details_spec.rb b/spec/requests/user_details_spec.rb
index d2997b4a..2811cca0 100644
--- a/spec/requests/user_details_spec.rb
+++ b/spec/requests/user_details_spec.rb
@@ -3,7 +3,6 @@
 RSpec.describe 'the user details page' do
   before do
     mock_notifications_endpoint!
-    mock_user_with_multiple_suppliers_endpoint!
     mock_suppliers_endpoint!
     mock_email_verification_pending_endpoint!
     mock_user_auth_logs_endpoint!
@@ -12,6 +11,7 @@
   describe 'visiting the user profile page' do
     it 'shows the user details' do
       stub_signed_in_user
+      mock_user_with_multiple_suppliers_endpoint!
 
       get user_detail_path
 
@@ -23,11 +23,77 @@
       expect(response.body).to include 'Bandersnatch'
       expect(response.body).to include 'San Junipero'
     end
+
+    context 'when the user can deactivate their account' do
+      it 'shows the deactivate account option' do
+        stub_signed_in_user
+        mock_user_with_multiple_suppliers_endpoint!
+
+        get user_detail_path
+
+        expect(response).to be_successful
+        expect(response.body).to include 'Deactivate account'
+      end
+    end
+
+    context 'when the user cannot deactivate their account' do
+      it 'does not show the deactivate account option' do
+        stub_signed_in_user
+        mock_user_who_cannot_deactivate_endpoint!
+
+        get user_detail_path
+
+        expect(response).to be_successful
+        expect(response.body).not_to include 'Deactivate my account'
+      end
+    end
+  end
+
+  describe 'GET /user_detail/deactivate' do
+    context 'when the user can deactivate their account' do
+      it 'renders the deactivate confirmation page' do
+        stub_signed_in_user
+        mock_user_with_multiple_suppliers_endpoint!
+
+        get deactivate_confirmation_user_detail_path
+
+        expect(response).to be_successful
+        expect(response.body).to include 'Deactivate my account'
+      end
+    end
+
+    context 'when deactivating the account is successful' do
+      it 'redirects to the sign out page with a notice' do
+        stub_signed_in_user
+        mock_user_with_multiple_suppliers_endpoint!
+        mock_deactivate_user_endpoint!
+
+        patch deactivate_user_detail_path
+
+        expect(response).to redirect_to(root_path)
+        expect(flash[:notice]).to eq 'Your account has been deactivated.'
+      end
+    end
+
+    context 'when the user cannot deactivate their account' do
+      it 'redirects to the user profile page with an alert' do
+        stub_signed_in_user
+        mock_user_who_cannot_deactivate_endpoint!
+
+        get deactivate_confirmation_user_detail_path
+
+        expect(response).to redirect_to(user_detail_path)
+        follow_redirect!
+
+        expect(response.body).to include 'You cannot deactivate your account because you are the only active user for'
+      end
+    end
   end
 
   describe 'GET /user_detail/edit' do
     it 'renders the edit form' do
       stub_signed_in_user
+      mock_user_with_multiple_suppliers_endpoint!
 
       get edit_user_detail_path
 
@@ -41,6 +107,7 @@
   describe 'PATCH /user_detail' do
     it 'updates the user name and redirects to the profile page on success' do
       stub_signed_in_user
+      mock_user_with_multiple_suppliers_endpoint!
       mock_update_user_name_endpoint!
 
       patch user_detail_path, params: { name: 'New Name' }
@@ -53,6 +120,7 @@
 
     it 're-renders the edit form with an error message on failure' do
       stub_signed_in_user
+      mock_user_with_multiple_suppliers_endpoint!
       mock_update_user_name_endpoint_failure!
 
       patch user_detail_path, params: { name: 'New Name' }
@@ -63,6 +131,7 @@
 
     it 'handles connection errors gracefully' do
       stub_signed_in_user
+      mock_user_with_multiple_suppliers_endpoint!
       mock_update_user_name_endpoint_connection_error!
 
       patch user_detail_path, params: { name: 'New Name' }
diff --git a/spec/support/api_helpers.rb b/spec/support/api_helpers.rb
index 3213d532..09a5b438 100644
--- a/spec/support/api_helpers.rb
+++ b/spec/support/api_helpers.rb
@@ -387,6 +387,30 @@ def mock_user_with_multiple_suppliers_endpoint!
       )
   end
 
+  def mock_user_who_cannot_deactivate_endpoint!
+    stub_request(:get, api_url("users?filter[auth_id]=#{JWT.encode(mock_auth_id, 'test')}"))
+      .to_return(
+        headers: json_headers,
+        body: json_fixture_file('user_who_cannot_deactivate.json')
+      )
+  end
+
+  def mock_user_who_can_deactivate_endpoint!
+    stub_request(:get, api_url("users?filter[auth_id]=#{JWT.encode(mock_auth_id, 'test')}"))
+      .to_return(
+        headers: json_headers,
+        body: json_fixture_file('user_who_can_deactivate.json')
+      )
+  end
+
+  def mock_deactivate_user_endpoint!
+    stub_request(:patch, api_url('users/deactivate'))
+      .to_return(
+        headers: json_headers,
+        body: json_fixture_file('user_deactivated.json')
+      )
+  end
+
   def mock_customer_effort_score_endpoint!
     feedback_params = {
       data: {