diff --git a/spec/services/order_invoice_comparator_spec.rb b/spec/services/order_invoice_comparator_spec.rb
index 5470fa3929..c3cd679179 100644
--- a/spec/services/order_invoice_comparator_spec.rb
+++ b/spec/services/order_invoice_comparator_spec.rb
@@ -115,19 +115,217 @@ describe OrderInvoiceComparator do
       end
     end
 
-    context "a non-relevant associated model is updated" do
-      let(:distributor){ order.distributor }
-      it "returns false" do
-        distributor.update!(name: 'THIS IS A NEW NAME', abn: 'This is a new ABN')
-        expect(subject).to be false
-      end
-    end
+    context "changes on an associated order object" do
+      describe "detecting relevant associated object changes" do
+        context "adjustment changes" do
+          it "creating a new adjustment returns true" do
+            create(:adjustment, order_id: order.id)
+            order.reload
+            expect(subject).to be true
+          end
 
-    context "a relevant associated object is updated" do
-      let(:line_item){ order.line_items.first }
-      it "return true" do
-        line_item.update!(quantity: line_item.quantity + 1)
-        expect(subject).to be true
+          context "with an existing adjustment" do
+            let!(:adjustment) { create(:adjustment, order_id: order.id) }
+
+            it "editing the amount returns true" do
+              adjustment.update!(amount: 123)
+              order.reload
+              expect(subject).to be true
+            end
+
+            it "changing the adjustment type" do
+              adjustment.update!(adjustable_type: "Spree::Payment")
+              order.reload
+              expect(subject).to be true
+            end
+
+            it "deleting the label" do
+              order.all_adjustments.destroy_all
+              order.reload
+              expect(subject).to be true
+            end
+          end
+        end
+
+        context "line item changes" do
+          let(:line_item){ order.line_items.first }
+
+          context "on quantitity" do
+            it "return true" do
+              line_item.update!(quantity: line_item.quantity + 1)
+              expect(subject).to be true
+            end
+          end
+
+          context "on variant id" do
+            it "return true" do
+              line_item.update!(variant_id: Spree::Variant.first.id)
+              order.reload
+              expect(subject).to be true
+            end
+          end
+        end
+
+        context "bill address changes on" do
+          let(:bill_address) { Spree::Address.where(id: order.bill_address_id) }
+          it "first name" do
+            bill_address.update!(firstname: "Jane")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "last name" do
+            bill_address.update!(lastname: "Jones")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "address (1)" do
+            bill_address.update!(address1: "Rue du Fromage 66")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "address (2)" do
+            bill_address.update!(address2: "South by Southwest")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "city" do
+            bill_address.update!(city: "Antibes")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "zipcode" do
+            bill_address.update!(zipcode: "04229")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "phone" do
+            bill_address.update!(phone: "111-222-333")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "company" do
+            bill_address.update!(company: "A Company Name")
+            order.reload
+            expect(subject).to be true
+          end
+        end
+
+        context "ship address changes on" do
+          let(:ship_address) { Spree::Address.where(id: order.ship_address_id) }
+          it "first name" do
+            ship_address.update!(firstname: "Jane")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "last name" do
+            ship_address.update!(lastname: "Jones")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "address (1)" do
+            ship_address.update!(address1: "Rue du Fromage 66")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "address (2)" do
+            ship_address.update!(address2: "South by Southwest")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "city" do
+            ship_address.update!(city: "Antibes")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "zipcode" do
+            ship_address.update!(zipcode: "04229")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "phone" do
+            ship_address.update!(phone: "111-222-333")
+            order.reload
+            expect(subject).to be true
+          end
+
+          it "company" do
+            ship_address.update!(company: "A Company Name")
+            order.reload
+            expect(subject).to be true
+          end
+        end
+
+        context "customer changes on" do
+          let(:customer){ order.customer }
+
+          context "code" do
+            it "return false" do
+              customer.update!(code: 98_754)
+              order.reload
+              expect(subject).to be false
+            end
+          end
+
+          context "email" do
+            it "return false" do
+              customer.update!(email: "customer@email.org")
+              order.reload
+              expect(subject).to be false
+            end
+          end
+        end
+
+        context "payment changes on" do
+          let(:payment) { create(:payment, order_id: order.id) }
+          context "amount" do
+            it "returns true" do
+              payment.update!(amount: 222)
+              order.reload
+              expect(subject).to be true
+            end
+          end
+
+          context "payment method" do
+            let(:payment_method) { create(:payment_method) }
+
+            it "returns true" do
+              payment.update!(payment_method_id: payment_method.id)
+              order.reload
+              expect(subject).to be true
+            end
+          end
+        end
+      end
+
+      describe "ignoring non-relevant associated object changes" do
+        context "customer changes" do
+          let(:customer){ create(:customer) }
+          it "returns false" do
+            order.update!(customer_id: customer.id)
+            expect(subject).to be false
+          end
+        end
+
+        context "distributor changes" do
+          let(:distributor){ order.distributor }
+          it "returns false" do
+            distributor.update!(name: 'THIS IS A NEW NAME', abn: 'This is a new ABN')
+            expect(subject).to be false
+          end
+        end
       end
     end
   end
@@ -159,6 +357,20 @@ describe OrderInvoiceComparator do
         order.reload
         expect(subject).to be false
       end
+
+      context "payment changes on" do
+        context "state" do
+          let(:payment) { order.payments.first }
+          it "returns true" do
+            expect {
+              payment.started_processing
+            }.to change { payment.state }.from("checkout").to("processing")
+
+            order.reload
+            expect(subject).to be true
+          end
+        end
+      end
     end
 
     context "a non-relevant associated model is updated" do
@@ -170,11 +382,25 @@ describe OrderInvoiceComparator do
     end
 
     context "a relevant associated object is updated" do
-      let(:payment){ order.payments.first }
-      it "return true" do
-        expect(payment.state).to_not eq 'completed'
-        payment.update!(state: 'completed')
-        expect(subject).to be true
+      describe "detecting relevant associated object changes" do
+        context "adjustment changes" do
+          context "with an existing adjustment" do
+            let!(:adjustment) { create(:adjustment, order_id: order.id) }
+            it "changing the label returns true" do
+              adjustment.update!(label: "It's a new label")
+              order.reload
+              expect(subject).to be true
+            end
+          end
+        end
+        context "payment changes" do
+          let(:payment){ order.payments.first }
+          it "return true" do
+            expect(payment.state).to_not eq 'completed'
+            payment.update!(state: 'completed')
+            expect(subject).to be true
+          end
+        end
       end
     end
   end