diff --git a/app/assets/javascripts/application.js b/app/assets/javascripts/application.js
index 781c2de88..aae1e7072 100644
--- a/app/assets/javascripts/application.js
+++ b/app/assets/javascripts/application.js
@@ -27,6 +27,7 @@
 //= require dietary-restrictions
 //= require cocoon
 //= require font_awesome5
+//= require how-you-found-us
 
 $(function() {
   $("body").removeClass("no-js");
diff --git a/app/assets/javascripts/how-you-found-us.js b/app/assets/javascripts/how-you-found-us.js
new file mode 100644
index 000000000..20105c3fe
--- /dev/null
+++ b/app/assets/javascripts/how-you-found-us.js
@@ -0,0 +1,20 @@
+$(document).ready(function() {
+  const $otherRadioButton = $('#member_how_you_found_us_other');
+  const $otherReason = $('#member_how_you_found_us_other_reason');
+  const $elementToToggle = $otherReason.parent();
+
+  function toggleOtherReason() {
+    if ($otherRadioButton.is(':checked')) {
+      $elementToToggle.removeClass('d-none').hide().slideDown(50);
+      $otherReason.prop('disabled', false).focus(); // Optional — disabling is not needed
+    } else {
+      $elementToToggle.slideUp(50, function() {
+        $elementToToggle.addClass('d-none');
+        $otherReason.val('');
+      });
+    }
+  }
+
+  toggleOtherReason();
+  $('input[name="member[how_you_found_us]"]').on('change', toggleOtherReason);
+});
\ No newline at end of file
diff --git a/app/controllers/concerns/member_concerns.rb b/app/controllers/concerns/member_concerns.rb
index fa8f7eed4..1f4abffb6 100644
--- a/app/controllers/concerns/member_concerns.rb
+++ b/app/controllers/concerns/member_concerns.rb
@@ -10,8 +10,8 @@ module InstanceMethods
 
     def member_params
       params.require(:member).permit(
-        :pronouns, :name, :surname, :email, :mobile, :about_you, :skill_list, :newsletter, :other_dietary_restrictions,
-          dietary_restrictions: [],
+        :pronouns, :name, :surname, :email, :mobile, :about_you, :skill_list, :newsletter, :other_dietary_restrictions, :how_you_found_us,
+        :how_you_found_us_other_reason, dietary_restrictions: []
       ).tap do |params|
         # We want to keep Rails' hidden blank field in the form so that all dietary restrictions for a member can be
         # removed by submitting the form with all check boxes unticked. However, we want to remove the blank value
@@ -29,5 +29,14 @@ def suppress_notices
     def set_member
       @member = current_user
     end
+
+    def how_you_found_us_selections_valid?
+      how_found_present = member_params[:how_you_found_us].present?
+      other_reason_present = member_params[:how_you_found_us_other_reason].present?
+      return false if member_params[:how_you_found_us] == 'other' && !other_reason_present
+      return true if member_params[:how_you_found_us] == 'other' && other_reason_present
+
+      how_found_present != other_reason_present
+    end
   end
 end
diff --git a/app/controllers/member/details_controller.rb b/app/controllers/member/details_controller.rb
index 403e460d2..848a01e10 100644
--- a/app/controllers/member/details_controller.rb
+++ b/app/controllers/member/details_controller.rb
@@ -8,13 +8,26 @@ class Member::DetailsController < ApplicationController
 
   def edit
     accept_terms
-
     flash[notice] = I18n.t('notifications.signing_up')
     @member.newsletter ||= true
   end
 
   def update
-    return render :edit unless @member.update(member_params)
+    attrs = member_params
+    attrs[:how_you_found_us_other_reason] = nil if attrs[:how_you_found_us] != 'other'
+
+    unless how_you_found_us_selections_valid?
+      @member.errors.add(:how_you_found_us, 'You must select one option')
+      return render :edit
+    end
+    attrs[:how_you_found_us] = params[:member][:how_you_found_us] if params[:member][:how_you_found_us].present?
+
+    if params[:member][:how_you_found_us_other_reason].present? && attrs[:how_you_found_us] == 'other'
+      attrs[:how_you_found_us_other_reason] =
+        params[:member][:how_you_found_us_other_reason]
+    end
+
+    return render :edit unless @member.update(attrs)
 
     member_params[:newsletter] ? subscribe_to_newsletter(@member) : unsubscribe_from_newsletter(@member)
     redirect_to step2_member_path
diff --git a/app/models/member.rb b/app/models/member.rb
index 59ef29027..81b7d8905 100644
--- a/app/models/member.rb
+++ b/app/models/member.rb
@@ -1,6 +1,14 @@
 class Member < ApplicationRecord
   include Permissions
 
+  enum how_you_found_us: {
+    from_a_friend: 0,
+    search_engine: 1,
+    social_media: 2,
+    codebar_host_or_partner: 3,
+    other: 4
+  }
+
   has_many :attendance_warnings
   has_many :bans
   has_many :eligibility_inquiries
diff --git a/app/views/member/details/edit.html.haml b/app/views/member/details/edit.html.haml
index 1fc548ffe..37eefda82 100644
--- a/app/views/member/details/edit.html.haml
+++ b/app/views/member/details/edit.html.haml
@@ -19,6 +19,30 @@
           label_method:  ->(r) { r.humanize.upcase_first }
         = f.input :other_dietary_restrictions, placeholder: 'Other dietary restrictions',
             wrapper_html: { class: class_names('mt-n3', 'd-none': !@member.other_dietary_restrictions?) }, label_html: { class: 'sr-only' }
+        - if @member.errors.any?
+          #error_explanation
+            %h2= "#{pluralize(@member.errors.count, 'error')} prohibited this member from being saved:"
+            %ul
+              - @member.errors.full_messages.each do |msg|
+                %li= msg
+        - if @member.errors[:how_you_found_us]&.any?
+          %span.text-danger= @member.errors[:how_you_found_us].first
+        .col-12.mb-3
+          %fieldset
+            = f.input :how_you_found_us,
+                      as: :radio_buttons,
+                      collection: Member.how_you_found_us.keys,
+                      label_method: ->(option) { t("member.details.edit.how_you_found_us_options.#{option}") },
+                      value_method: :to_s,
+                      label: t('member.details.edit.how_you_found_us_label'),
+                      item_wrapper_class: 'form-check d-flex align-items-center mb-2',
+                      label_item: true,
+                      input_html: { class: 'form-check-input me-2', style: 'margin-top: 0;' },
+                      label_html: { class: 'form-check-label', style: 'margin-left: 0;' }
+
+            = f.input :how_you_found_us_other_reason,
+                label: t('member.details.edit.how_you_found_us_other_reason'),
+                input_html: { class: 'form-control w-100' }
         = f.input :newsletter, as: :boolean, checked_value: true, unchecked_value: false
         .text-right.mb-4
           = hidden_field_tag :next_page, step2_member_path(member_type: @type)
diff --git a/config/locales/en.yml b/config/locales/en.yml
index a9ccfb5ac..a3eaf9372 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -442,6 +442,14 @@ en:
       edit:
         title: Almost there...
         summary: We need some more details from you to finish creating your account. We use these to help run our events.
+        how_you_found_us_label: "How did you find out about us?*"
+        how_you_found_us_other_reason: "Please specify how you found us"
+        how_you_found_us_options:
+          from_a_friend: "From a friend"
+          search_engine: "Search engine (Google etc.)"
+          social_media: "Social media"
+          codebar_host_or_partner: "One of Codebar's hosts or partners"
+          other: "Other"
         coach:
           about_you: What experience do you have? What languages do you like to use? Tell us a little bit about yourself!
         student:
diff --git a/db/migrate/20250823151717_add_how_you_found_us_options.rb b/db/migrate/20250823151717_add_how_you_found_us_options.rb
new file mode 100644
index 000000000..b247c3a77
--- /dev/null
+++ b/db/migrate/20250823151717_add_how_you_found_us_options.rb
@@ -0,0 +1,6 @@
+class AddHowYouFoundUsOptions < ActiveRecord::Migration[7.0]
+  def change
+    add_column :members, :how_you_found_us, :integer
+    add_column :members, :how_you_found_us_other_reason, :string
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 5c5dbc99c..6c2636bc6 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2025_08_20_145012) do
+ActiveRecord::Schema[7.1].define(version: 2025_08_23_151717) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -397,6 +397,8 @@
     t.datetime "opt_in_newsletter_at", precision: nil
     t.enum "dietary_restrictions", default: [], array: true, enum_type: "dietary_restriction_enum"
     t.string "other_dietary_restrictions"
+    t.integer "how_you_found_us"
+    t.string "how_you_found_us_other_reason"
     t.index ["email"], name: "index_members_on_email", unique: true
   end
 
diff --git a/spec/controllers/member/details_controller_spec.rb b/spec/controllers/member/details_controller_spec.rb
new file mode 100644
index 000000000..9c98c487b
--- /dev/null
+++ b/spec/controllers/member/details_controller_spec.rb
@@ -0,0 +1,102 @@
+RSpec.describe Member::DetailsController do
+  render_views
+  let(:member) { Fabricate(:member) }
+
+  before do
+    allow(controller).to receive(:current_user).and_return(member)
+    allow_any_instance_of(Services::MailingList).to receive(:subscribe).and_return(true)
+  end
+
+  describe 'PATCH #update' do
+    context 'with valid params' do
+      it 'updates how_you_found_us with radio option' do
+        patch :update, params: {
+          id: member.id,
+          member: {
+            how_you_found_us: 'social_media',
+            newsletter: 'true'
+          }
+        }
+
+        member.reload
+        expect(I18n.t("member.details.edit.how_you_found_us_options.#{member.how_you_found_us}")).to eq('Social media')
+        expect(member.how_you_found_us_other_reason).to eq(nil)
+        expect(response).to redirect_to(step2_member_path)
+      end
+
+      it 'adds other_reason to how_you_found_us when provided' do
+        patch :update, params: {
+          id: member.id,
+          member: {
+            how_you_found_us: 'other',
+            how_you_found_us_other_reason: 'Saw a pamphlet',
+            newsletter: 'false'
+          },
+        }
+
+        member.reload
+        expect(member.how_you_found_us).to eq('other')
+        expect(member.how_you_found_us_other_reason).to eq('Saw a pamphlet')
+        expect(response).to redirect_to(step2_member_path)
+      end
+
+      it 'updates how_you_found_us with only other_reason' do
+        patch :update, params: {
+          id: member.id,
+          member: {
+            how_you_found_us: 'other',
+            how_you_found_us_other_reason: 'At a meetup',
+            newsletter: 'true'
+          },
+        }
+
+        member.reload
+        expect(member.how_you_found_us).to eq('other')
+        expect(member.how_you_found_us_other_reason).to eq('At a meetup')
+        expect(response).to redirect_to(step2_member_path)
+      end
+
+      it 'removes duplicates and blank entries' do
+        patch :update, params: {
+          id: member.id,
+          member: {
+            how_you_found_us: 'other',
+            how_you_found_us_other_reason: 'From a colleague',
+            newsletter: 'true'
+          },
+        }
+
+        member.reload
+        expect(member.how_you_found_us).to eq('other')
+        expect(member.how_you_found_us_other_reason).to eq('From a colleague')
+        expect(response).to redirect_to(step2_member_path)
+      end
+    end
+
+    context 'when update fails (invalid data)' do
+      it 'error raised when no how you found us selection given' do
+        patch :update, params: {
+          id: member.id,
+          member: {
+            how_you_found_us: 'other',
+            how_you_found_us_other_reason: nil,
+          }
+        }
+
+        expect(response.body).to include('You must select one option')
+      end
+
+      it 'error raised when both how you found us fields popoulated' do
+        patch :update, params: {
+          id: member.id,
+          member: {
+            how_you_found_us: 'from_a_friend',
+            how_you_found_us_other_reason: 'something else',
+          }
+        }
+
+        expect(response.body).to include('You must select one option')
+      end
+    end
+  end
+end
diff --git a/spec/features/member_joining_spec.rb b/spec/features/member_joining_spec.rb
index e8050b037..bf844bae7 100644
--- a/spec/features/member_joining_spec.rb
+++ b/spec/features/member_joining_spec.rb
@@ -15,7 +15,7 @@
   end
 
   scenario 'A visitor must fill in all mandatory fields in order to sign up' do
-    member = Fabricate(:member, name: nil, surname: nil, email: nil, about_you: nil)
+    member = Fabricate(:member, name: nil, surname: nil, email: nil, about_you: nil, how_you_found_us: nil, how_you_found_us_other_reason: nil)
     member.update(can_log_in: true)
     login member
 
@@ -27,6 +27,7 @@
     expect(page).to have_content "Surname can't be blank"
     expect(page).to have_content "Email address can't be blank"
     expect(page).to have_content "About you can't be blank"
+    expect(page).to have_content "You must select one option"
   end
 
   scenario 'A new member details are successfully captured' do
@@ -43,6 +44,11 @@
     check 'Vegan'
     check 'Other'
     fill_in 'Other dietary restrictions', with: 'peanut allergy'
+    find('#member_how_you_found_us_from_a_friend').click
+
+    find('#member_how_you_found_us_other').click
+    expect(page).to have_content('Please specify how you found us')
+    fill_in 'member_how_you_found_us_other_reason', with: 'found on a poster', id: true
     click_on 'Next'
 
     expect(page).to have_current_path(step2_member_path)
diff --git a/spec/features/subscribing_to_newsletter_spec.rb b/spec/features/subscribing_to_newsletter_spec.rb
index 38c24b940..7a166d009 100644
--- a/spec/features/subscribing_to_newsletter_spec.rb
+++ b/spec/features/subscribing_to_newsletter_spec.rb
@@ -27,6 +27,7 @@
       fill_in 'member_surname', with: 'Doe'
       fill_in 'member_email', with: 'jane@codebar.io'
       fill_in 'member_about_you', with: Faker::Lorem.paragraph
+      find('#member_how_you_found_us_from_a_friend').click
 
       click_on 'Next'
     end
@@ -46,6 +47,8 @@
       fill_in 'member_surname', with: 'Doe'
       fill_in 'member_email', with: 'jane@codebar.io'
       fill_in 'member_about_you', with: Faker::Lorem.paragraph
+      find('#member_how_you_found_us_other').click
+      fill_in 'member_how_you_found_us_other_reason', with: Faker::Lorem.paragraph, id: true
 
       uncheck 'newsletter'