diff --git a/app/models/enterprise.rb b/app/models/enterprise.rb
index 4adfb05309..39dd73a968 100644
--- a/app/models/enterprise.rb
+++ b/app/models/enterprise.rb
@@ -56,6 +56,7 @@ class Enterprise < ActiveRecord::Base
 
 
   validates :name, presence: true
+  validate :name_is_unique
   validates :sells, presence: true, inclusion: {in: SELLS}
   validates :address, presence: true, associated: true
   validates :email, presence: true
@@ -333,6 +334,15 @@ class Enterprise < ActiveRecord::Base
 
   private
 
+  def name_is_unique
+    dups = Enterprise.where(name: name)
+    dups = dups.where('id != ?', id) unless new_record?
+
+    if dups.any?
+      errors.add :name, "has already been taken. If this is your enterprise and you would like to claim ownership, please contact the current manager of this profile at #{dups.first.owner.email}."
+    end
+  end
+
   def email_is_known?
     owner.enterprises.confirmed.map(&:email).include?(email)
   end
diff --git a/db/migrate/20150612045544_make_enterprises_name_unique.rb b/db/migrate/20150612045544_make_enterprises_name_unique.rb
new file mode 100644
index 0000000000..5722284d94
--- /dev/null
+++ b/db/migrate/20150612045544_make_enterprises_name_unique.rb
@@ -0,0 +1,20 @@
+class MakeEnterprisesNameUnique < ActiveRecord::Migration
+  def up
+    dup_names = Enterprise.group('name').select('name, COUNT(*) AS num_enterprises')
+
+    dup_names.each do |data|
+      (data.num_enterprises.to_i - 1).times do |i|
+        e = Enterprise.find_by_name data.name
+        new_name = "#{data.name}-#{i+1}"
+        e.update_column :name, new_name
+        say "Renamed enterprise #{data.name} to #{new_name}"
+      end
+    end
+
+    add_index :enterprises, :name, unique: true
+  end
+
+  def down
+    remove_index :enterprises, :name
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index dd00ce3f4e..055f828e9d 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20150605052516) do
+ActiveRecord::Schema.define(:version => 20150612045544) do
 
   create_table "adjustment_metadata", :force => true do |t|
     t.integer "adjustment_id"
@@ -322,6 +322,7 @@ ActiveRecord::Schema.define(:version => 20150605052516) do
   add_index "enterprises", ["address_id"], :name => "index_enterprises_on_address_id"
   add_index "enterprises", ["confirmation_token"], :name => "index_enterprises_on_confirmation_token", :unique => true
   add_index "enterprises", ["is_primary_producer", "sells"], :name => "index_enterprises_on_is_primary_producer_and_sells"
+  add_index "enterprises", ["name"], :name => "index_enterprises_on_name", :unique => true
   add_index "enterprises", ["owner_id"], :name => "index_enterprises_on_owner_id"
   add_index "enterprises", ["permalink"], :name => "index_enterprises_on_permalink", :unique => true
   add_index "enterprises", ["sells"], :name => "index_enterprises_on_sells"
diff --git a/spec/models/enterprise_spec.rb b/spec/models/enterprise_spec.rb
index 388d80258e..4fb6ac621a 100644
--- a/spec/models/enterprise_spec.rb
+++ b/spec/models/enterprise_spec.rb
@@ -179,6 +179,31 @@ describe Enterprise do
         }.to raise_error ActiveRecord::RecordInvalid, "Validation failed: Owner can't be blank"
     end
 
+    describe "name uniqueness" do
+      let(:owner) { create(:user, email: 'owner@example.com') }
+      let!(:enterprise) { create(:enterprise, name: 'Enterprise', owner: owner) }
+
+      it "prevents duplicate names for new records" do
+        e = Enterprise.new name: enterprise.name
+        e.should_not be_valid
+        e.errors[:name].first.should ==
+          "has already been taken. If this is your enterprise and you would like to claim ownership, please contact the current manager of this profile at owner@example.com."
+      end
+
+      it "prevents duplicate names for existing records" do
+        e = create(:enterprise, name: 'foo')
+        e.name = enterprise.name
+        e.should_not be_valid
+        e.errors[:name].first.should ==
+          "has already been taken. If this is your enterprise and you would like to claim ownership, please contact the current manager of this profile at owner@example.com."
+      end
+
+      it "does not prohibit the saving of an enterprise with no name clash" do
+        enterprise.email = 'new@email.com'
+        enterprise.should be_valid
+      end
+    end
+
     describe "preferred_shopfront_taxon_order" do
       it "empty strings are valid" do
         enterprise = build(:enterprise, preferred_shopfront_taxon_order: "")