diff --git a/app/jobs/one_time_jobs/backfill_card_grant_settings.rb b/app/jobs/one_time_jobs/backfill_card_grant_settings.rb
new file mode 100644
index 0000000000..081ecf7883
--- /dev/null
+++ b/app/jobs/one_time_jobs/backfill_card_grant_settings.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+module OneTimeJobs
+  class BackfillCardGrantSettings
+    def self.perform
+      CardGrant.find_each do |cg|
+        default_card_grant_setting = CardGrantSetting.find_by(event_id: cg.id)
+        ActiveRecord::Base.transaction do
+          card_grant_setting = CardGrantSetting.find_or_create_by!(card_grant_id: cg.id)
+          card_grant_setting.update!({
+                                       banned_categories: cg.banned_categories || default_card_grant_setting.banned_categories,
+                                       banned_merchants: cg.banned_merchants || default_card_grant_setting.banned_merchants,
+                                       category_lock: cg.category_lock || default_card_grant_setting.category_lock,
+                                       expiration_preference: default_card_grant_setting.expiration_preference,
+                                       invite_message: default_card_grant_setting.invite_message,
+                                       keyword_lock: cg.keyword_lock || default_card_grant_setting.keyword_lock,
+                                       merchant_lock: cg.merchant_lock || default_card_grant_setting.merchant_lock,
+                                       pre_authorization_required: cg.pre_authorization_required || default_card_grant_setting.pre_authorization_required,
+                                       reimbursement_conversions_enabled: default_card_grant_setting.reimbursement_conversions_enabled
+                                     })
+        end
+      end
+    end
+
+  end
+end
diff --git a/app/mailers/card_grant_mailer.rb b/app/mailers/card_grant_mailer.rb
index c2472cd761..df89b26849 100644
--- a/app/mailers/card_grant_mailer.rb
+++ b/app/mailers/card_grant_mailer.rb
@@ -3,7 +3,7 @@
 class CardGrantMailer < ApplicationMailer
   def card_grant_notification
     @card_grant = params[:card_grant]
-    @custom_invite_message = @card_grant.setting.invite_message
+    @custom_invite_message = @card_grant.invite_message
     purpose_text = " for #{@card_grant.purpose}"
 
     mail to: @card_grant.user.email_address_with_name, subject: "[#{@card_grant.event.name}] You've received a #{@card_grant.amount.format} grant#{purpose_text if @card_grant.purpose.present?}!"
diff --git a/app/models/card_grant.rb b/app/models/card_grant.rb
index 6d3da94705..b830e355e8 100644
--- a/app/models/card_grant.rb
+++ b/app/models/card_grant.rb
@@ -60,8 +60,10 @@ class CardGrant < ApplicationRecord
   belongs_to :sent_by, class_name: "User"
   belongs_to :disbursement, optional: true
   has_many :disbursements, ->(record) { where(destination_subledger_id: record.subledger_id).or(where(source_subledger_id: record.subledger_id)) }, through: :event
-  has_one :card_grant_setting, through: :event, required: true
+  has_one :default_card_grant_setting, through: :event, required: true
+  has_one :card_grant_setting
   alias_method :setting, :card_grant_setting
+  alias_method :default_setting, :default_card_grant_setting
 
   enum :status, { active: 0, canceled: 1, expired: 2 }, default: :active
 
@@ -243,11 +245,11 @@ def create_stripe_card(session)
   end
 
   def allowed_merchants
-    (merchant_lock + (setting&.merchant_lock || [])).uniq
+    (merchant_lock || setting&.merchant_lock || default_setting&.merchant_lock || []).uniq
   end
 
   def disallowed_merchants
-    (banned_merchants + (setting&.banned_merchants || [])).uniq
+    (banned_merchants || setting&.banned_merchants || default_setting&.banned_merchants || []).uniq
   end
 
   def allowed_merchant_names
@@ -255,11 +257,11 @@ def allowed_merchant_names
   end
 
   def allowed_categories
-    (category_lock + (setting&.category_lock || [])).uniq
+    (category_lock || setting&.category_lock || default_setting&.category_lock || []).uniq
   end
 
   def disallowed_categories
-    (banned_categories + (setting&.banned_categories || [])).uniq
+    (banned_categories || setting&.banned_categories || default_setting&.banned_categories || []).uniq
   end
 
   def allowed_category_names
@@ -267,7 +269,7 @@ def allowed_category_names
   end
 
   def keyword_lock
-    super || setting&.keyword_lock
+    setting&.keyword_lock || default_setting&.keyword_lock
   end
 
   def expires_after
@@ -278,6 +280,10 @@ def expires_on
     created_at + expires_after.days
   end
 
+  def invite_message
+    setting&.invite_message || default_setting&.invite_message
+  end
+
   def last_user_change_to(...)
     user_id = versions.where_object_changes_to(...).last&.whodunnit
 
@@ -307,7 +313,19 @@ def convert_to_reimbursement_report!
   private
 
   def create_card_grant_setting
-    CardGrantSetting.find_or_create_by!(event_id:)
+    default_card_grant_setting = CardGrantSetting.find_or_create_by!(event_id:)
+    card_grant_setting = CardGrantSetting.find_or_create_by!(card_grant_id: id)
+    card_grant_setting.update!({
+                                 banned_categories: self.banned_categories || default_card_grant_setting.banned_categories,
+                                 banned_merchants: self.banned_merchants || default_card_grant_setting.banned_merchants,
+                                 category_lock: self.category_lock || default_card_grant_setting.category_lock,
+                                 expiration_preference: default_card_grant_setting.expiration_preference,
+                                 invite_message: default_card_grant_setting.invite_message,
+                                 keyword_lock: self.keyword_lock || default_card_grant_setting.keyword_lock,
+                                 merchant_lock: self.merchant_lock || default_card_grant_setting.merchant_lock,
+                                 pre_authorization_required: self.pre_authorization_required || default_card_grant_setting.pre_authorization_required,
+                                 reimbursement_conversions_enabled: default_card_grant_setting.reimbursement_conversions_enabled
+                               })
   end
 
   def create_user
diff --git a/app/models/card_grant_setting.rb b/app/models/card_grant_setting.rb
index 1969ea2e64..6d41a81303 100644
--- a/app/models/card_grant_setting.rb
+++ b/app/models/card_grant_setting.rb
@@ -14,11 +14,13 @@
 #  merchant_lock                     :string
 #  pre_authorization_required        :boolean          default(FALSE), not null
 #  reimbursement_conversions_enabled :boolean          default(TRUE), not null
-#  event_id                          :bigint           not null
+#  card_grant_id                     :bigint
+#  event_id                          :bigint
 #
 # Indexes
 #
-#  index_card_grant_settings_on_event_id  (event_id)
+#  index_card_grant_settings_on_card_grant_id  (card_grant_id)
+#  index_card_grant_settings_on_event_id       (event_id)
 #
 # Foreign Keys
 #
@@ -34,6 +36,7 @@ class CardGrantSetting < ApplicationRecord
   alias_attribute :allowed_categories, :category_lock
   alias_attribute :disallowed_merchants, :banned_merchants
   has_many :card_grants, through: :event
+  belongs_to :card_grant
 
   enum :expiration_preference, {
     "90 days": 90,
diff --git a/app/models/event.rb b/app/models/event.rb
index 8e160d5cac..93a8647a91 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -418,6 +418,10 @@ def ancestor_organizer_positions
     self.activated_at = Time.now
   end
 
+  before_save if: -> { plan.card_grants_enabled? } do
+    create_card_grant_setting!
+  end
+
   before_validation do
     build_plan(type: parent&.subevent_plan&.class || parent&.plan&.class || Event::Plan::Standard) if plan.nil?
   end
diff --git a/app/views/events/edit.html.erb b/app/views/events/edit.html.erb
index 9e50301336..5810ed1496 100644
--- a/app/views/events/edit.html.erb
+++ b/app/views/events/edit.html.erb
@@ -21,7 +21,7 @@
           <%= link_to "Reimbursements", edit_event_path(@event, tab: "reimbursements"), data: { turbo: true, turbo_action: "advance" } %>
         <% end %>
       <% end %>
-      <% if @event.card_grant_setting.present? %>
+      <% if @event.plan.card_grants_enabled? %>
         <%= settings_tab active: @settings_tab == "card_grants" do %>
           <%= link_to "Card grants", edit_event_path(@event, tab: "card_grants"), data: { turbo: true, turbo_action: "advance" } %>
         <% end %>
diff --git a/app/views/events/settings/_card_grants.html.erb b/app/views/events/settings/_card_grants.html.erb
index 607e95d3db..08ee3e7ca7 100644
--- a/app/views/events/settings/_card_grants.html.erb
+++ b/app/views/events/settings/_card_grants.html.erb
@@ -39,6 +39,7 @@
           <div class="field--checkbox--switch" style="flex-shrink:0">
             <%= card_grant_setting_fields.label :reimbursement_conversions_enabled do %>
               <%= card_grant_setting_fields.check_box :reimbursement_conversions_enabled,
+                disabled:,
                 switch: true %>
               <span class="slider"></span>
             <% end %>
@@ -55,6 +56,7 @@
           <div class="field--checkbox--switch" style="flex-shrink:0">
             <%= card_grant_setting_fields.label :pre_authorization_required do %>
               <%= card_grant_setting_fields.check_box :pre_authorization_required,
+                disabled:,
                 switch: true %>
               <span class="slider"></span>
             <% end %>
diff --git a/db/migrate/20250807195557_add_card_grant_to_card_grant_setting.rb b/db/migrate/20250807195557_add_card_grant_to_card_grant_setting.rb
new file mode 100644
index 0000000000..61115a817b
--- /dev/null
+++ b/db/migrate/20250807195557_add_card_grant_to_card_grant_setting.rb
@@ -0,0 +1,11 @@
+class AddCardGrantToCardGrantSetting < ActiveRecord::Migration[7.2]
+  disable_ddl_transaction!
+
+  def up
+    add_reference :card_grant_settings, :card_grant, index: {algorithm: :concurrently}
+  end
+
+  def down
+    remove_reference :card_grant_settings, :card_grant, index: {algorithm: :concurrently}
+  end
+end
diff --git a/db/migrate/20250807201752_make_event_id_on_card_grant_setting_nullable.rb b/db/migrate/20250807201752_make_event_id_on_card_grant_setting_nullable.rb
new file mode 100644
index 0000000000..3becea559e
--- /dev/null
+++ b/db/migrate/20250807201752_make_event_id_on_card_grant_setting_nullable.rb
@@ -0,0 +1,9 @@
+class MakeEventIdOnCardGrantSettingNullable < ActiveRecord::Migration[7.2]
+  def up
+    change_column_null :card_grant_settings, :event_id, true
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration, "this migration cannot be reversed because event id may be null"
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 4340e83711..0cb207c3d1 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -12,7 +12,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.2].define(version: 2025_08_02_222150) do
+ActiveRecord::Schema[7.2].define(version: 2025_08_07_201752) do
   create_schema "google_sheets"
 
   # These are extensions that must be enabled in order to support this database
@@ -455,7 +455,7 @@
   end
 
   create_table "card_grant_settings", force: :cascade do |t|
-    t.bigint "event_id", null: false
+    t.bigint "event_id"
     t.string "merchant_lock"
     t.string "category_lock"
     t.string "invite_message"
@@ -465,6 +465,8 @@
     t.boolean "pre_authorization_required", default: false, null: false
     t.string "banned_merchants"
     t.string "banned_categories"
+    t.bigint "card_grant_id"
+    t.index ["card_grant_id"], name: "index_card_grant_settings_on_card_grant_id"
     t.index ["event_id"], name: "index_card_grant_settings_on_event_id"
   end