diff --git a/app/models/ticket.rb b/app/models/ticket.rb
index ac7727f6..e805ad89 100644
--- a/app/models/ticket.rb
+++ b/app/models/ticket.rb
@@ -15,4 +15,7 @@ class Ticket < ActiveRecord::Base
 	has_one :nonprofit, through: :event
 	has_many :activities, as: :attachment, dependent: :destroy
 
+	def related_tickets
+		payment.tickets.where('id != ?', self.id)
+	end
 end
diff --git a/spec/models/ticket_spec.rb b/spec/models/ticket_spec.rb
new file mode 100644
index 00000000..33ab7ecf
--- /dev/null
+++ b/spec/models/ticket_spec.rb
@@ -0,0 +1,35 @@
+# License: AGPL-3.0-or-later WITH Web-Template-Output-Additional-Permission-3.0-or-later
+require 'rails_helper'
+
+RSpec.describe Ticket, type: :model do
+  let(:payment1) { force_create(:payment)}
+  let(:payment2) { force_create(:payment)}
+  let(:ticket1) { force_create(:ticket, payment: payment1)}
+  let(:ticket2) { force_create(:ticket, payment: payment1)}
+  let(:ticket3) { force_create(:ticket, payment: payment1)}
+  let(:ticket4) { force_create(:ticket, payment: payment2)}
+
+  before(:each) do
+    ticket1 
+    ticket2 
+    ticket3 
+    ticket4 
+  end
+
+  it 'has ticket1 getting ticket2 and ticket3 for related_tickets' do
+    expect(ticket1.related_tickets).to contain_exactly(ticket2, ticket3)
+  end
+
+  it 'has ticket2 getting ticket1 and ticket3 for related_tickets' do
+    expect(ticket2.related_tickets).to contain_exactly(ticket1, ticket3)
+  end
+
+
+  it 'has ticket3 getting ticket1 and ticket2 for related_tickets' do
+    expect(ticket3.related_tickets).to contain_exactly(ticket1, ticket2)
+  end
+
+  it 'has ticket4 getting no related tickets' do
+    expect(ticket4.related_tickets).to be_empty
+  end
+end