diff --git a/app/jobs/update_bill_items.rb b/app/jobs/update_bill_items.rb
index 00dfd333db..c8e156778c 100644
--- a/app/jobs/update_bill_items.rb
+++ b/app/jobs/update_bill_items.rb
@@ -1,4 +1,4 @@
-UpdateBillItems = Struct.new(:lala) do
+UpdateBillItems = Struct.new("UpdateBillItems") do
   def perform
     # If it is the first of the month, calculate turnover for the previous month up until midnight last night
     # Otherwise, calculate turnover for the current month
@@ -9,56 +9,50 @@ UpdateBillItems = Struct.new(:lala) do
 
     # Cycle through enterprises
     enterprises.each do |enterprise|
+      start_for_enterprise = [start_date, enterprise.created_at].max
+      #end_for_enterprise = [start_date, enterprise.deleted].min
+
       # Cycle through previous versions of this enterprise
-      versions = enterprise.versions.where('created_at >= (?)', start_date)
-      bill_items = []
+      versions = enterprise.versions.where('created_at >= (?)', start_for_enterprise).order(:created_at)
 
       trial_start = enterprise.shop_trial_start_date
       trial_expiry = enterprise.shop_trial_expiry
 
       versions.each do |version|
-        begins_at = bill_items.last.andand.ends_at || [start_date, enterprise.created_at].max
+        begins_at = version.previous.andand.created_at || start_for_enterprise
         ends_at = version.created_at
 
-        split_for_trial(version.reify, begins_at, ends_at, trial_start, trial_expiry).each do |bill_item|
-          bill_items << bill_item
-        end
+        split_for_trial(version.reify, begins_at, ends_at, trial_start, trial_expiry)
       end
 
       # Update / create bill_item for current start
-      begins_at = bill_items.last.andand.ends_at || [start_date, enterprise.created_at].max
+      begins_at = versions.last.andand.created_at || start_for_enterprise
       ends_at = end_date
 
-      split_for_trial(enterprise, begins_at, ends_at, trial_start, trial_expiry).each do |bill_item|
-        bill_items << bill_item
-      end
+      split_for_trial(enterprise, begins_at, ends_at, trial_start, trial_expiry)
     end
   end
 
   def split_for_trial(enterprise, begins_at, ends_at, trial_start, trial_expiry)
-    bill_items = []
-
     trial_start = trial_expiry = begins_at-1.day if trial_start.nil? || trial_expiry.nil?
 
     # If the trial begins after ends_at, create a bill for the entire period
     # Otherwise, create a normal bill_item from the begins_at until the start of the trial
     if trial_start > begins_at
-      bill_items << update_bill_item(enterprise, begins_at, [ends_at, trial_start].min, false)
+      update_bill_item(enterprise, begins_at, [ends_at, trial_start].min, false)
     end
 
     # If all or some of the trial occurs between begins_at and ends_at
     # Create a trial bill_item from the from begins_at or trial_start, whichever occurs last, until ends_at, or trial_expiry whichever occurs first
     if trial_expiry >= begins_at && trial_start <= ends_at
-      bill_items << update_bill_item(enterprise, [trial_start, begins_at].max, [ends_at, trial_expiry].min, true)
+      update_bill_item(enterprise, [trial_start, begins_at].max, [ends_at, trial_expiry].min, true)
     end
 
     # If the trial finishes before begins_at, or trial has not been set, create a bill for the entire period
     # Otherwise, create a normal bill_item from the end of the trial until ends_at
     if trial_expiry < ends_at
-      bill_items << update_bill_item(enterprise, [trial_expiry, begins_at].max, ends_at, false)
+      update_bill_item(enterprise, [trial_expiry, begins_at].max, ends_at, false)
     end
-
-    bill_items
   end
 
   def update_bill_item(enterprise, begins_at, ends_at, trial)
@@ -66,9 +60,36 @@ UpdateBillItems = Struct.new(:lala) do
     sells = enterprise.sells
     orders = Spree::Order.where('distributor_id = (?) AND completed_at >= (?) AND completed_at < (?)', enterprise.id, begins_at, ends_at)
 
-    bill_item = BillItem.where(begins_at: begins_at, sells: sells, trial: trial, owner_id: owner_id, enterprise_id: enterprise.id).first
-    bill_item ||= BillItem.new(begins_at: begins_at, sells: sells, trial: trial, owner_id: owner_id, enterprise_id: enterprise.id)
-    bill_item.update_attributes({ends_at: ends_at, turnover: orders.sum(&:total)})
+    # Snagging any BillItems which overlap
+    overlapping_bill_items = BillItem.where('begins_at <= (?) AND ends_at >= (?) AND enterprise_id = (?)',ends_at, begins_at, enterprise.id)
+    overlapping_bill_items.each do |bill_item|
+      if bill_item.sells != sells || bill_item.trial != trial || bill_item.owner_id != owner_id
+        Bugsnag.notify(RuntimeError.new("Duplicate BillItem"), {
+          bill_items: {
+            new: {
+              begins_at: begins_at,
+              ends_at: ends_at,
+              sells: sells,
+              trial: trial,
+              turnover: orders.sum(&:total),
+              owner_id: owner_id,
+              enterprise_id: enterprise.id
+            }.as_json,
+            existing: bill_item.as_json
+          }
+        })
+      end
+    end
+
+    bill_item = BillItem.where(begins_at: begins_at, enterprise_id: enterprise.id).first
+    bill_item ||= BillItem.new(begins_at: begins_at, enterprise_id: enterprise.id)
+    bill_item.update_attributes({
+      ends_at: ends_at,
+      sells: sells,
+      trial: trial,
+      owner_id: owner_id,
+      turnover: orders.sum(&:total)
+    })
 
     bill_item
   end
diff --git a/spec/factories.rb b/spec/factories.rb
index 169d2d5c02..57b0c95106 100644
--- a/spec/factories.rb
+++ b/spec/factories.rb
@@ -215,6 +215,16 @@ FactoryGirl.define do
     code { SecureRandom.base64(150) }
     user
   end
+
+  factory :bill_item do
+    begins_at { Time.now.beginning_of_month }
+    ends_at { Time.now.beginning_of_month + 1.month }
+    sells { ['none', 'own', 'any'].sample }
+    trial { [true, false].sample }
+    enterprise
+    owner { FactoryGirl.create :user }
+    turnover { BigDecimal.new("#{rand(5000)}.#{rand(99)}") }
+  end
 end
 
 
diff --git a/spec/jobs/update_bill_items_spec.rb b/spec/jobs/update_bill_items_spec.rb
index 6d94999f22..828a5b706e 100644
--- a/spec/jobs/update_bill_items_spec.rb
+++ b/spec/jobs/update_bill_items_spec.rb
@@ -1,7 +1,379 @@
 require 'spec_helper'
 
+def travel_to(time)
+  around { |example| Timecop.travel(start_of_july + time) { example.run } }
+end
+
 describe UpdateBillItems do
-  describe "smoke tests" do
+  describe "unit tests" do
+    let!(:start_of_july) { Time.now.beginning_of_year + 6.months }
+
+    let!(:updater) { UpdateBillItems.new }
+
+    describe "perform", versioning: true do
+      let!(:enterprise) { create(:supplier_enterprise, created_at: start_of_july - 1.month, sells: 'any') }
+
+      before do
+        allow(Enterprise).to receive(:select) { [enterprise] }
+      end
+
+      context "on the first of the month" do
+        travel_to(3.hours)
+
+        it "processes the previous month" do
+          expect(updater).to receive(:split_for_trial)
+          .with(enterprise, start_of_july - 1.month, start_of_july, nil, nil)
+          updater.perform
+        end
+      end
+
+      context "on all other days" do
+        travel_to(1.day + 3.hours)
+
+        it "processes the current month up until previous midnight" do
+          expect(updater).to receive(:split_for_trial)
+          .with(enterprise, start_of_july, start_of_july + 1.day, nil, nil)
+          updater.perform
+        end
+      end
+
+      context "when an enterprise is created before the beginning of the current month" do
+        travel_to(28.days)
+
+        context "when no alterations to sells or owner have been made during the current month" do
+
+          it "begins at the start of the month" do
+            expect(updater).to receive(:split_for_trial)
+            .with(enterprise, start_of_july, start_of_july + 28.days, nil, nil)
+            updater.perform
+          end
+        end
+
+        context "when sells has been changed within the current month" do
+          before do
+            Timecop.freeze(start_of_july + 10.days) do
+              # NOTE: Sells is changed between when order1 and order2 are placed
+              enterprise.update_attribute(:sells, 'own')
+            end
+          end
+
+          travel_to(28.days)
+
+          it "processes each sells period separately" do
+            allow(updater).to receive(:split_for_trial).twice
+            updater.perform
+
+            expect(updater).to have_received(:split_for_trial)
+            .with(enterprise.versions.first.reify, start_of_july, start_of_july + 10.days, nil, nil)
+
+            expect(updater).to have_received(:split_for_trial)
+            .with(enterprise, start_of_july + 10.days, start_of_july + 28.days, nil, nil)
+          end
+        end
+
+        context "when owner has been changed within the current month" do
+          let!(:new_owner) { create(:user) }
+
+          before do
+            Timecop.freeze(start_of_july + 10.days) do
+              # NOTE: Sells is changed between when order1 and order2 are placed
+              enterprise.update_attribute(:owner, new_owner)
+            end
+          end
+
+          travel_to(28.days)
+
+          it "processes each ownership period separately" do
+            allow(updater).to receive(:split_for_trial).twice
+            updater.perform
+
+            expect(updater).to have_received(:split_for_trial)
+            .with(enterprise.versions.first.reify, start_of_july, start_of_july + 10.days, nil, nil)
+
+            expect(updater).to have_received(:split_for_trial)
+            .with(enterprise, start_of_july + 10.days, start_of_july + 28.days, nil, nil)
+          end
+        end
+
+        context "when some other attribute has been changed within the current month" do
+          before do
+            Timecop.freeze(start_of_july + 10.days) do
+              # NOTE: Sells is changed between when order1 and order2 are placed
+              enterprise.update_attribute(:name, 'Some New Name')
+            end
+          end
+
+          travel_to(28.days)
+
+          it "does not create a version, and so does not split the period" do
+            expect(enterprise.versions).to eq []
+            allow(updater).to receive(:split_for_trial).once
+            updater.perform
+            expect(updater).to have_received(:split_for_trial)
+            .with(enterprise, start_of_july, start_of_july + 28.days, nil, nil)
+          end
+        end
+
+        context "where sells or owner_id were altered during the previous month (ie. June)" do
+          let!(:new_owner) { create(:user) }
+
+          before do
+            Timecop.freeze(start_of_july - 20.days) do
+              # NOTE: Sells is changed between when order1 and order2 are placed
+              enterprise.update_attribute(:sells, 'own')
+            end
+            Timecop.freeze(start_of_july - 10.days) do
+              # NOTE: Sells is changed between when order1 and order2 are placed
+              enterprise.update_attribute(:owner, new_owner)
+            end
+          end
+
+          travel_to(28.days)
+
+          it "ignores those verions" do
+            allow(updater).to receive(:split_for_trial).once
+            updater.perform
+            expect(updater).to have_received(:split_for_trial)
+            .with(enterprise, start_of_july, start_of_july + 28.days, nil, nil)
+          end
+        end
+      end
+
+      context "when an enterprise is created during the current month" do
+        before do
+          enterprise.update_attribute(:created_at, start_of_july + 10.days)
+        end
+
+        travel_to(28.days)
+
+        it "begins at the date the enterprise was created" do
+          allow(updater).to receive(:split_for_trial).once
+          updater.perform
+          expect(updater).to have_received(:split_for_trial)
+          .with(enterprise, start_of_july + 10.days, start_of_july + 28.days, nil, nil)
+        end
+      end
+
+      pending "when an enterprise is deleted during the current month" do
+        before do
+          enterprise.update_attribute(:deleted_at, start_of_july + 20.days)
+        end
+
+        travel_to(28.days)
+
+        it "ends at the date the enterprise was deleted" do
+          allow(updater).to receive(:split_for_trial)
+          updater.perform
+          expect(updater).to have_received(:split_for_trial)
+          .with(enterprise, start_of_july, start_of_july + 20.days, nil, nil)
+        end
+      end
+    end
+
+    describe "split_for_trial" do
+      let!(:enterprise) { double(:enterprise) }
+      let(:begins_at) { start_of_july }
+      let(:ends_at) { begins_at + 30.days }
+
+      context "when trial_start is nil" do
+        let(:trial_start) { nil }
+        let(:trial_expiry) { begins_at + 3.days }
+
+        before do
+          allow(updater).to receive(:update_bill_item).once
+          updater.split_for_trial(enterprise, begins_at, ends_at, trial_start, trial_expiry)
+        end
+
+        it "calls update_bill_item once for the entire period" do
+          expect(updater).to have_received(:update_bill_item)
+          .with(enterprise, begins_at, ends_at, false)
+        end
+      end
+
+      context "when trial_expiry is nil" do
+        let(:trial_start) { begins_at + 3.days }
+        let(:trial_expiry) { nil }
+
+        before do
+          allow(updater).to receive(:update_bill_item).once
+          updater.split_for_trial(enterprise, begins_at, ends_at, trial_start, trial_expiry)
+        end
+
+        it "calls update_bill_item once for the entire period" do
+          expect(updater).to have_received(:update_bill_item)
+          .with(enterprise, begins_at, ends_at, false)
+        end
+      end
+
+      context "when the trial begins before begins_at" do
+        let(:trial_start) { begins_at - 10.days }
+
+        context "and the trial ends before begins_at" do
+          let(:trial_expiry) { begins_at - 5.days }
+
+          before do
+            allow(updater).to receive(:update_bill_item).once
+            updater.split_for_trial(enterprise, begins_at, ends_at, trial_start, trial_expiry)
+          end
+
+          it "calls update_bill_item once for the entire period" do
+            expect(updater).to have_received(:update_bill_item)
+            .with(enterprise, begins_at, ends_at, false)
+          end
+        end
+
+        context "and the trial ends after begins_at" do
+          let(:trial_expiry) { begins_at + 5.days }
+
+          before do
+            allow(updater).to receive(:update_bill_item).twice
+            updater.split_for_trial(enterprise, begins_at, ends_at, trial_start, trial_expiry)
+          end
+
+          it "calls update_bill_item once for the trial period" do
+            expect(updater).to have_received(:update_bill_item)
+            .with(enterprise, begins_at, trial_expiry, true)
+          end
+
+          it "calls update_bill_item once for the non-trial period" do
+            expect(updater).to have_received(:update_bill_item)
+            .with(enterprise, trial_expiry, ends_at, false)
+          end
+        end
+
+        context "and the trial ends after ends_at" do
+          let(:trial_expiry) { ends_at + 5.days }
+
+          before do
+            allow(updater).to receive(:update_bill_item).once
+            updater.split_for_trial(enterprise, begins_at, ends_at, trial_start, trial_expiry)
+          end
+
+          it "calls update_bill_item once for the entire (trial) period" do
+            expect(updater).to have_received(:update_bill_item)
+            .with(enterprise, begins_at, ends_at, true)
+          end
+        end
+      end
+
+      context "when the trial begins after begins_at" do
+        let(:trial_start) { begins_at + 5.days }
+
+        context "and the trial begins after ends_at" do
+          let(:trial_start) { ends_at + 5.days }
+          let(:trial_expiry) { ends_at + 10.days }
+
+          before do
+            allow(updater).to receive(:update_bill_item).once
+            updater.split_for_trial(enterprise, begins_at, ends_at, trial_start, trial_expiry)
+          end
+
+          it "calls update_bill_item once for the entire period" do
+            expect(updater).to have_received(:update_bill_item)
+            .with(enterprise, begins_at, ends_at, false)
+          end
+        end
+
+        context "and the trial ends before ends_at" do
+          let(:trial_expiry) { ends_at - 2.days }
+
+          before do
+            allow(updater).to receive(:update_bill_item).exactly(3).times
+            updater.split_for_trial(enterprise, begins_at, ends_at, trial_start, trial_expiry)
+          end
+
+          it "calls update_bill_item once for the non-trial period before the trial" do
+            expect(updater).to have_received(:update_bill_item)
+            .with(enterprise, begins_at, trial_start, false)
+          end
+
+          it "calls update_bill_item once for the trial period" do
+            expect(updater).to have_received(:update_bill_item)
+            .with(enterprise, trial_start, trial_expiry, true)
+          end
+
+          it "calls update_bill_item once for the non-trial period after the trial" do
+            expect(updater).to have_received(:update_bill_item)
+            .with(enterprise, trial_expiry, ends_at, false)
+          end
+        end
+
+        context "and the trial ends after ends_at" do
+          let(:trial_expiry) { ends_at + 5.days }
+
+          before do
+            allow(updater).to receive(:update_bill_item).twice
+            updater.split_for_trial(enterprise, begins_at, ends_at, trial_start, trial_expiry)
+          end
+
+          it "calls update_bill_item once for the non-trial period" do
+            expect(updater).to have_received(:update_bill_item)
+            .with(enterprise, begins_at, trial_start, false)
+          end
+
+          it "calls update_bill_item once for the trial period" do
+            expect(updater).to have_received(:update_bill_item)
+            .with(enterprise, trial_start, ends_at, true)
+          end
+        end
+      end
+    end
+
+    describe "update_bill_item" do
+      let!(:enterprise) { create(:enterprise, sells: 'any') }
+
+      let!(:existing) { create(:bill_item, enterprise: enterprise, begins_at: start_of_july) }
+
+      context "when arguments match both 'begins_at' and 'enterprise_id' of an existing bill item" do
+        it "updates the existing bill item" do
+          expect{
+            updater.update_bill_item(enterprise, start_of_july, start_of_july + 20.days, false)
+          }.to_not change{ BillItem.count }
+          existing.reload
+          expect(existing.owner_id).to eq enterprise.owner_id
+          expect(existing.ends_at).to eq start_of_july + 20.days
+          expect(existing.sells).to eq enterprise.sells
+          expect(existing.trial).to eq false
+        end
+      end
+
+      context "when 'begins_at' does not match an existing bill item" do
+        before do
+          expect{
+            updater.update_bill_item(enterprise, start_of_july + 20.days, start_of_july + 30.days, false)
+          }.to change{ BillItem.count }.from(1).to(2)
+        end
+
+        it "creates a new existing bill item" do
+          bill_item = BillItem.last
+          expect(bill_item.owner_id).to eq enterprise.owner_id
+          expect(bill_item.ends_at).to eq start_of_july + 30.days
+          expect(bill_item.sells).to eq enterprise.sells
+          expect(bill_item.trial).to eq false
+        end
+      end
+
+      context "when 'enterprise_id' does not match an existing bill item" do
+        let!(:new_enterprise) { create(:enterprise, sells: 'own') }
+
+        before do
+          expect{
+            updater.update_bill_item(new_enterprise, start_of_july, start_of_july + 20.days, false)
+          }.to change{ BillItem.count }.from(1).to(2)
+        end
+
+        it "creates a new existing bill item" do
+          bill_item = BillItem.last
+          expect(bill_item.owner_id).to eq new_enterprise.owner_id
+          expect(bill_item.ends_at).to eq start_of_july + 20.days
+          expect(bill_item.sells).to eq new_enterprise.sells
+          expect(bill_item.trial).to eq false
+        end
+      end
+    end
+  end
+
+  describe "validation tests" do
     # Chose july to test with because June has 30 days and so is easy to calculate end date for shop trial
     let!(:start_of_july) { Time.now.beginning_of_year + 6.months }
 
@@ -23,7 +395,7 @@ describe UpdateBillItems do
         enterprise.update_attribute(:created_at, start_of_july - 2.months)
       end
 
-      context "where the sells property of the enterprise has not been altered within the current billing period" do
+      context "where the sells and owner_id properties of the enterprise have not been altered within the current billing period" do
         before do
           Timecop.travel(start_of_july + 28.days)
         end
@@ -34,7 +406,7 @@ describe UpdateBillItems do
 
         context "where no trial information has been set" do
           before do
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -52,7 +424,7 @@ describe UpdateBillItems do
         context "where a trial ended during the current billing period" do
           before do
             enterprise.update_attribute(:shop_trial_start_date, start_of_july - 10.days)
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -72,7 +444,7 @@ describe UpdateBillItems do
         context "where the trial began part-way through the current billing period" do
           before do
             enterprise.update_attribute(:shop_trial_start_date, start_of_july + 10.days)
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -106,7 +478,7 @@ describe UpdateBillItems do
 
         context "where no trial information has been set" do
           before do
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -126,7 +498,7 @@ describe UpdateBillItems do
         context "where a trial ended during the current billing period, after sells was changed" do
           before do
             enterprise.update_attribute(:shop_trial_start_date, start_of_july - 10.days)
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -147,7 +519,7 @@ describe UpdateBillItems do
         context "where a trial ended during the current billing period, before sells was changed" do
           before do
             enterprise.update_attribute(:shop_trial_start_date, start_of_july - 22.days)
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -168,7 +540,7 @@ describe UpdateBillItems do
         context "where the trial began part-way through the current billing period, after sells was changed" do
           before do
             enterprise.update_attribute(:shop_trial_start_date, start_of_july + 18.days)
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -189,7 +561,7 @@ describe UpdateBillItems do
         context "where the trial began part-way through the current billing period, before sells was changed" do
           before do
             enterprise.update_attribute(:shop_trial_start_date, start_of_july + 8.days)
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -207,6 +579,142 @@ describe UpdateBillItems do
           end
         end
       end
+
+      context "where the owner_id property of the enterprise has been altered within the current billing period" do
+        let!(:original_owner) { enterprise.owner }
+        let!(:new_owner) { create(:user) }
+
+        before do
+          Timecop.freeze(start_of_july + 10.days) do
+            # NOTE: Sells is changed between when order1 and order2 are placed
+            enterprise.update_attribute(:owner, new_owner)
+          end
+
+          Timecop.travel(start_of_july + 28.days)
+        end
+
+        after do
+          Timecop.return
+        end
+
+        context "where no trial information has been set" do
+          before do
+            UpdateBillItems.new.perform
+          end
+
+          let(:bill_items) { BillItem.order(:id) }
+
+          it "splits the billing period into a separate item for each owner" do
+            expect(bill_items.count).to eq 2
+            expect(bill_items.map(&:owner_id)).to eq [original_owner.id, new_owner.id]
+            expect(bill_items.map(&:sells)).to eq ['any', 'any']
+            expect(bill_items.map(&:trial)).to eq [false, false]
+            expect(bill_items.map(&:begins_at)).to eq [start_of_july, start_of_july + 10.days]
+            expect(bill_items.map(&:ends_at)).to eq [start_of_july + 10.days, start_of_july + 28.days]
+          end
+
+          it "splits the turnover for the month to date" do
+            expect(bill_items.first.turnover).to eq order1.total
+            expect(bill_items.last.turnover).to eq order2.total + order3.total
+          end
+        end
+
+        context "where a trial ended during the current billing period, after owner was changed" do
+          before do
+            enterprise.update_attribute(:shop_trial_start_date, start_of_july - 10.days)
+            UpdateBillItems.new.perform
+          end
+
+          let(:bill_items) { BillItem.order(:id) }
+
+          it "splits out the distinct ownership periods and trial period into separate bill items" do
+            expect(bill_items.count).to eq 3
+            expect(bill_items.map(&:owner_id)).to eq [original_owner.id, new_owner.id, new_owner.id]
+            expect(bill_items.map(&:sells)).to eq ['any', 'any', 'any']
+            expect(bill_items.map(&:trial)).to eq [true, true, false]
+            expect(bill_items.map(&:begins_at)).to eq [start_of_july, start_of_july + 10.days, start_of_july + 20.days]
+            expect(bill_items.map(&:ends_at)).to eq [start_of_july + 10.days, start_of_july + 20.days, start_of_july + 28.days]
+          end
+
+          it "splits out the trial period into a separate bill item" do
+            expect(bill_items.first.turnover).to eq order1.total
+            expect(bill_items.second.turnover).to eq order2.total
+            expect(bill_items.last.turnover).to eq order3.total
+          end
+        end
+
+        context "where a trial ended during the current billing period, before owner was changed" do
+          before do
+            enterprise.update_attribute(:shop_trial_start_date, start_of_july - 22.days)
+            UpdateBillItems.new.perform
+          end
+
+          let(:bill_items) { BillItem.order(:id) }
+
+          it "splits out the distinct sells periods and trial period into separate bill items" do
+            expect(bill_items.count).to eq 3
+            expect(bill_items.map(&:owner_id)).to eq [original_owner.id, original_owner.id, new_owner.id]
+            expect(bill_items.map(&:sells)).to eq ['any', 'any', 'any']
+            expect(bill_items.map(&:trial)).to eq [true, false, false]
+            expect(bill_items.map(&:begins_at)).to eq [start_of_july,          start_of_july + 8.days,  start_of_july + 10.days]
+            expect(bill_items.map(&:ends_at)).to eq   [start_of_july + 8.days, start_of_july + 10.days, start_of_july + 28.days]
+          end
+
+          it "splits out the trial period into a separate bill item" do
+            expect(bill_items.first.turnover).to eq order1.total
+            expect(bill_items.second.turnover).to eq 0
+            expect(bill_items.last.turnover).to eq (order2.total + order3.total)
+          end
+        end
+
+        context "where the trial began part-way through the current billing period, after owner was changed" do
+          before do
+            enterprise.update_attribute(:shop_trial_start_date, start_of_july + 18.days)
+            UpdateBillItems.new.perform
+          end
+
+          let(:bill_items) { BillItem.order(:id) }
+
+          it "splits out the distinct ownership periods and trial period into separate bill items" do
+            expect(bill_items.count).to eq 3
+            expect(bill_items.map(&:owner_id)).to eq [original_owner.id, new_owner.id, new_owner.id]
+            expect(bill_items.map(&:sells)).to eq ['any', 'any', 'any']
+            expect(bill_items.map(&:trial)).to eq [false, false, true]
+            expect(bill_items.map(&:begins_at)).to eq [start_of_july,           start_of_july + 10.days, start_of_july + 18.days]
+            expect(bill_items.map(&:ends_at)).to eq   [start_of_july + 10.days, start_of_july + 18.days, start_of_july + 28.days]
+          end
+
+          it "splits out the trial period into a separate bill item" do
+            expect(bill_items.first.turnover).to eq order1.total
+            expect(bill_items.second.turnover).to eq order2.total
+            expect(bill_items.last.turnover).to eq order3.total
+          end
+        end
+
+        context "where the trial began part-way through the current billing period, before owner was changed" do
+          before do
+            enterprise.update_attribute(:shop_trial_start_date, start_of_july + 8.days)
+            UpdateBillItems.new.perform
+          end
+
+          let(:bill_items) { BillItem.order(:id) }
+
+          it "splits out the distinct ownership periods and trial period into separate bill items" do
+            expect(bill_items.count).to eq 3
+            expect(bill_items.map(&:owner_id)).to eq [original_owner.id, original_owner.id, new_owner.id]
+            expect(bill_items.map(&:sells)).to eq ['any', 'any', 'any']
+            expect(bill_items.map(&:trial)).to eq [false, true, true]
+            expect(bill_items.map(&:begins_at)).to eq [start_of_july,          start_of_july + 8.days,  start_of_july + 10.days]
+            expect(bill_items.map(&:ends_at)).to eq   [start_of_july + 8.days, start_of_july + 10.days, start_of_july + 28.days]
+          end
+
+          it "splits out the trial period into a separate bill item" do
+            expect(bill_items.first.turnover).to eq order1.total
+            expect(bill_items.second.turnover).to eq 0
+            expect(bill_items.last.turnover).to eq (order2.total + order3.total)
+          end
+        end
+      end
     end
 
     context "where the enterprise was created after the beginning of the current billing period", versioning: true do
@@ -225,7 +733,7 @@ describe UpdateBillItems do
 
         context "where no trial information has been set" do
           before do
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -246,7 +754,7 @@ describe UpdateBillItems do
         context "where a trial ended during the current billing period" do
           before do
             enterprise.update_attribute(:shop_trial_start_date, start_of_july - 10.days)
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -268,7 +776,7 @@ describe UpdateBillItems do
         context "where the trial began part-way through the current billing period" do
           before do
             enterprise.update_attribute(:shop_trial_start_date, start_of_july + 10.days)
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -304,7 +812,7 @@ describe UpdateBillItems do
 
         context "where no trial information has been set" do
           before do
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -326,7 +834,7 @@ describe UpdateBillItems do
         context "where a trial ended during the current billing period, after sells was changed" do
           before do
             enterprise.update_attribute(:shop_trial_start_date, start_of_july - 10.days)
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -349,7 +857,7 @@ describe UpdateBillItems do
         context "where a trial ended during the current billing period, before sells was changed" do
           before do
             enterprise.update_attribute(:shop_trial_start_date, start_of_july - 22.days)
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -372,7 +880,7 @@ describe UpdateBillItems do
         context "where the trial began part-way through the current billing period, after sells was changed" do
           before do
             enterprise.update_attribute(:shop_trial_start_date, start_of_july + 18.days)
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }
@@ -395,7 +903,7 @@ describe UpdateBillItems do
         context "where the trial began part-way through the current billing period, before sells was changed" do
           before do
             enterprise.update_attribute(:shop_trial_start_date, start_of_july + 8.days)
-            UpdateBillItems.new('lala').perform
+            UpdateBillItems.new.perform
           end
 
           let(:bill_items) { BillItem.order(:id) }