diff --git a/db/migrate/20250513122703_add_uniqueness_to_subscriptions.rb b/db/migrate/20250513122703_add_uniqueness_to_subscriptions.rb
new file mode 100644
index 00000000..f97b67f9
--- /dev/null
+++ b/db/migrate/20250513122703_add_uniqueness_to_subscriptions.rb
@@ -0,0 +1,6 @@
+class AddUniquenessToSubscriptions < ActiveRecord::Migration[7.2]
+  def change
+    remove_index :subscriptions, :family_id
+    add_index :subscriptions, :family_id, unique: true
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 6d76a125..c9ba49e5 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[7.2].define(version: 2025_05_09_182903) do
+ActiveRecord::Schema[7.2].define(version: 2025_05_13_122703) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pgcrypto"
   enable_extension "plpgsql"
@@ -580,7 +580,7 @@ ActiveRecord::Schema[7.2].define(version: 2025_05_09_182903) do
     t.datetime "trial_ends_at"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
-    t.index ["family_id"], name: "index_subscriptions_on_family_id"
+    t.index ["family_id"], name: "index_subscriptions_on_family_id", unique: true
   end
 
   create_table "syncs", id: :uuid, default: -> { "gen_random_uuid()" }, force: :cascade do |t|