diff --git a/app/services/exports/export_donations_csv_service.rb b/app/services/exports/export_donations_csv_service.rb
index 9ca5bcb73f..8b5629f538 100644
--- a/app/services/exports/export_donations_csv_service.rb
+++ b/app/services/exports/export_donations_csv_service.rb
@@ -15,6 +15,13 @@ def initialize(donation_ids:, organization:)
       ).order(created_at: :asc)
 
       @organization = organization
+      item_header_names = @organization.items.select("DISTINCT ON (LOWER(name)) items.name").order("LOWER(name) ASC").map(&:name)
+
+      @item_headers = if @organization.include_in_kind_values_in_exported_files
+        item_header_names.flat_map { |header| [header, "#{header} In-Kind Value"] }
+      else
+        item_header_names
+      end
     end
 
     def generate_csv
@@ -42,7 +49,7 @@ def generate_csv_data
 
     def headers
       # Build the headers in the correct order
-      base_headers + item_headers
+      base_headers + @item_headers
     end
 
     # Returns a Hash of keys to indexes so that obtaining the index
@@ -95,24 +102,6 @@ def base_headers
       base_table.keys
     end
 
-    def item_headers
-      return @item_headers if @item_headers
-
-      item_names = Set.new
-
-      donations.each do |donation|
-        donation.line_items.each do |line_item|
-          item_names.add(line_item.item.name)
-        end
-      end
-
-      @item_headers = item_names.sort
-
-      @item_headers = @item_headers.flat_map { |header| [header, "#{header} In-Kind Value"] } if @organization.include_in_kind_values_in_exported_files
-
-      @item_headers
-    end
-
     def build_row_data(donation)
       row = base_table.values.map { |closure| closure.call(donation) }
       row += make_item_quantity_and_value_slots
@@ -128,7 +117,7 @@ def build_row_data(donation)
     end
 
     def make_item_quantity_and_value_slots
-      slots = Array.new(item_headers.size, 0)
+      slots = Array.new(@item_headers.size, 0)
       slots = slots.map.with_index { |value, index| index.odd? ? Money.new(0) : value } if @organization.include_in_kind_values_in_exported_files
       slots
     end
diff --git a/spec/fixtures/files/donations_export.csv b/spec/fixtures/files/donations_export.csv
new file mode 100644
index 0000000000..cb965506f3
--- /dev/null
+++ b/spec/fixtures/files/donations_export.csv
@@ -0,0 +1,5 @@
+Source,Date,Details,Storage Location,Quantity of Items,Variety of Items,In-Kind Total,Comments,A Item,B Item,C Item,Dupe Item,E Item
+Product Drive,2025-01-01,Test Product Drive,Test Storage Location,15,2,94.0,It's a fine day for diapers.,7,0,0,8,0
+Manufacturer,2025-01-01,Test Manufacturer,Test Storage Location,1,1,20.0,It's a fine day for diapers.,0,1,0,0,0
+Donation Site,2025-01-01,Test Donation Site,Test Storage Location,2,1,60.0,It's a fine day for diapers.,0,0,2,0,0
+Misc. Donation,2025-01-01,It's a fine day for...,Test Storage Location,3,1,120.0,It's a fine day for diapers.,0,0,0,0,3
diff --git a/spec/fixtures/files/donations_export_case_insensitive_sort.csv b/spec/fixtures/files/donations_export_case_insensitive_sort.csv
new file mode 100644
index 0000000000..3ee4652516
--- /dev/null
+++ b/spec/fixtures/files/donations_export_case_insensitive_sort.csv
@@ -0,0 +1,2 @@
+Source,Date,Details,Storage Location,Quantity of Items,Variety of Items,In-Kind Total,Comments,apple,Banana,Zebra
+Misc. Donation,2025-01-01,It's a fine day for...,Test Storage Location,2,1,3.0,It's a fine day for diapers.,0,2,0
diff --git a/spec/fixtures/files/donations_export_with_in_kind_values.csv b/spec/fixtures/files/donations_export_with_in_kind_values.csv
new file mode 100644
index 0000000000..1e8507cee0
--- /dev/null
+++ b/spec/fixtures/files/donations_export_with_in_kind_values.csv
@@ -0,0 +1,5 @@
+Source,Date,Details,Storage Location,Quantity of Items,Variety of Items,In-Kind Total,Comments,A Item,A Item In-Kind Value,B Item,B Item In-Kind Value,C Item,C Item In-Kind Value,Dupe Item,Dupe Item In-Kind Value,E Item,E Item In-Kind Value
+Product Drive,2025-01-01,Test Product Drive,Test Storage Location,15,2,94.0,It's a fine day for diapers.,7,70.00,0,0.00,0,0.00,8,24.00,0,0.00
+Manufacturer,2025-01-01,Test Manufacturer,Test Storage Location,1,1,20.0,It's a fine day for diapers.,0,0.00,1,20.00,0,0.00,0,0.00,0,0.00
+Donation Site,2025-01-01,Test Donation Site,Test Storage Location,2,1,60.0,It's a fine day for diapers.,0,0.00,0,0.00,2,60.00,0,0.00,0,0.00
+Misc. Donation,2025-01-01,It's a fine day for...,Test Storage Location,3,1,120.0,It's a fine day for diapers.,0,0.00,0,0.00,0,0.00,0,0.00,3,120.00
diff --git a/spec/fixtures/files/donations_export_with_inactive_item.csv b/spec/fixtures/files/donations_export_with_inactive_item.csv
new file mode 100644
index 0000000000..c616901b9d
--- /dev/null
+++ b/spec/fixtures/files/donations_export_with_inactive_item.csv
@@ -0,0 +1,5 @@
+Source,Date,Details,Storage Location,Quantity of Items,Variety of Items,In-Kind Total,Comments,A Item,A Item In-Kind Value,B Item,B Item In-Kind Value,C Item,C Item In-Kind Value,Dupe Item,Dupe Item In-Kind Value,E Item,E Item In-Kind Value,Inactive Item,Inactive Item In-Kind Value
+Product Drive,2025-01-01,Test Product Drive,Test Storage Location,15,2,94.0,It's a fine day for diapers.,7,70.00,0,0.00,0,0.00,8,24.00,0,0.00,0,0.00
+Manufacturer,2025-01-01,Test Manufacturer,Test Storage Location,1,1,20.0,It's a fine day for diapers.,0,0.00,1,20.00,0,0.00,0,0.00,0,0.00,0,0.00
+Donation Site,2025-01-01,Test Donation Site,Test Storage Location,2,1,60.0,It's a fine day for diapers.,0,0.00,0,0.00,2,60.00,0,0.00,0,0.00,0,0.00
+Misc. Donation,2025-01-01,It's a fine day for...,Test Storage Location,3,1,120.0,It's a fine day for diapers.,0,0.00,0,0.00,0,0.00,0,0.00,3,120.00,0,0.00
diff --git a/spec/fixtures/files/donations_export_with_unused_item.csv b/spec/fixtures/files/donations_export_with_unused_item.csv
new file mode 100644
index 0000000000..b91505deb0
--- /dev/null
+++ b/spec/fixtures/files/donations_export_with_unused_item.csv
@@ -0,0 +1,5 @@
+Source,Date,Details,Storage Location,Quantity of Items,Variety of Items,In-Kind Total,Comments,A Item,A Item In-Kind Value,B Item,B Item In-Kind Value,C Item,C Item In-Kind Value,Dupe Item,Dupe Item In-Kind Value,E Item,E Item In-Kind Value,Unused Item,Unused Item In-Kind Value
+Product Drive,2025-01-01,Test Product Drive,Test Storage Location,15,2,94.0,It's a fine day for diapers.,7,70.00,0,0.00,0,0.00,8,24.00,0,0.00,0,0.00
+Manufacturer,2025-01-01,Test Manufacturer,Test Storage Location,1,1,20.0,It's a fine day for diapers.,0,0.00,1,20.00,0,0.00,0,0.00,0,0.00,0,0.00
+Donation Site,2025-01-01,Test Donation Site,Test Storage Location,2,1,60.0,It's a fine day for diapers.,0,0.00,0,0.00,2,60.00,0,0.00,0,0.00,0,0.00
+Misc. Donation,2025-01-01,It's a fine day for...,Test Storage Location,3,1,120.0,It's a fine day for diapers.,0,0.00,0,0.00,0,0.00,0,0.00,3,120.00,0,0.00
diff --git a/spec/services/exports/export_donations_csv_service_spec.rb b/spec/services/exports/export_donations_csv_service_spec.rb
index 89ec120140..2d9dc2c5cc 100644
--- a/spec/services/exports/export_donations_csv_service_spec.rb
+++ b/spec/services/exports/export_donations_csv_service_spec.rb
@@ -7,10 +7,11 @@
     let(:donation_ids) { donations.map(&:id) }
     let(:duplicate_item) { create(:item, name: "Dupe Item", value_in_cents: 300, organization: organization) }
 
-    let(:donation_items_and_quantities) {
+    let(:donation_definitions) {
       [
         {
-          source: :product_drive_donation,
+          factory: :product_drive_donation,
+          attributes: {product_drive: create(:product_drive, name: "Test Product Drive", organization: organization)},
           items: [
             [duplicate_item, 5],
             [create(:item, name: "A Item", value_in_cents: 1000, organization: organization), 7],
@@ -18,73 +19,93 @@
           ]
         },
         {
-          source: :manufacturer_donation,
+          factory: :manufacturer_donation,
+          attributes: {manufacturer: create(:manufacturer, name: "Test Manufacturer", organization: organization)},
           items: [[create(:item, name: "B Item", value_in_cents: 2000, organization: organization), 1]]
         },
         {
-          source: :donation_site_donation,
+          factory: :donation_site_donation,
+          attributes: {donation_site: create(:donation_site, name: "Test Donation Site", organization: organization)},
           items: [[create(:item, name: "C Item", value_in_cents: 3000, organization: organization), 2]]
         },
         {
-          source: :donation,
+          factory: :donation,
+          attributes: {},
           items: [[create(:item, name: "E Item", value_in_cents: 4000, organization: organization), 3]]
         }
       ]
     }
 
     let(:donations) do
-      donation_items_and_quantities.each_with_index.map do |items_quantities, i|
+      donation_definitions.map do |definition|
         donation = create(
-          items_quantities[:source],
+          definition[:factory],
           storage_location: storage_location,
           organization: organization,
           issued_at: "2025-01-01",
-          comment: "It's a fine day for diapers."
+          comment: "It's a fine day for diapers.",
+          **definition[:attributes]
         )
 
-        items_quantities[:items].each do |line_item|
-          donation.line_items << create(:line_item, item: line_item[0], quantity: line_item[1])
+        definition[:items].each do |(item, quantity)|
+          donation.line_items << create(:line_item, item: item, quantity: quantity)
         end
 
         donation
       end
     end
 
-    def source_name(donation)
-      if !donation.product_drive.nil?
-        donation.product_drive.name
-      elsif !donation.manufacturer.nil?
-        donation.manufacturer.name
-      elsif !donation.donation_site.nil?
-        donation.donation_site.name
-      end
+    def expected_csv(fixture_name)
+      Rails.root.join("spec/fixtures/files", fixture_name).read
     end
 
     context 'while "Include in-kind value in donation and distribution exports?" is set to no' do
       it 'should match the expected content without in-kind value of each item for the csv' do
-        csv = <<~CSV
-          Source,Date,Details,Storage Location,Quantity of Items,Variety of Items,In-Kind Total,Comments,A Item,B Item,C Item,Dupe Item,E Item
-          Product Drive,2025-01-01,#{source_name(donations[0])},Test Storage Location,15,2,94.0,It's a fine day for diapers.,7,0,0,8,0
-          Manufacturer,2025-01-01,#{source_name(donations[1])},Test Storage Location,1,1,20.0,It's a fine day for diapers.,0,1,0,0,0
-          Donation Site,2025-01-01,#{source_name(donations[2])},Test Storage Location,2,1,60.0,It's a fine day for diapers.,0,0,2,0,0
-          Misc. Donation,2025-01-01,It's a fine day for...,Test Storage Location,3,1,120.0,It's a fine day for diapers.,0,0,0,0,3
-        CSV
-        expect(subject).to eq(csv)
+        expect(subject).to eq(expected_csv("donations_export.csv"))
       end
     end
 
     context 'while "Include in-kind value in donation and distribution exports?" is set to yes' do
-      it 'should match the expected content with in-kind value of each item for the csv' do
+      before do
         allow(organization).to receive(:include_in_kind_values_in_exported_files).and_return(true)
+      end
+
+      it 'should match the expected content with in-kind value of each item for the csv' do
+        expect(subject).to eq(expected_csv("donations_export_with_in_kind_values.csv"))
+      end
+
+      it 'should include inactive items in the export with zero quantities' do
+        create(:item, :inactive, name: "Inactive Item", organization: organization)
+
+        expect(subject).to eq(expected_csv("donations_export_with_inactive_item.csv"))
+      end
+
+      it 'should include items that are not in any donation with zero quantities' do
+        create(:item, name: "Unused Item", organization: organization)
+
+        expect(subject).to eq(expected_csv("donations_export_with_unused_item.csv"))
+      end
+    end
+
+    context 'when item names differ only by case' do
+      let(:donation_definitions) {
+        [
+          {
+            factory: :donation,
+            attributes: {},
+            items: [[create(:item, name: "Banana", value_in_cents: 150, organization: organization), 2]]
+          }
+        ]
+      }
+
+      it 'should sort item columns case-insensitively, ASC' do
+        # Create the other items in reverse-ASCII order to prove the sort is
+        # case-insensitive rather than relying on creation order or ASCII order
+        # (which would put "Zebra" before "apple").
+        create(:item, name: "apple", organization: organization)
+        create(:item, name: "Zebra", organization: organization)
 
-        csv = <<~CSV
-          Source,Date,Details,Storage Location,Quantity of Items,Variety of Items,In-Kind Total,Comments,A Item,A Item In-Kind Value,B Item,B Item In-Kind Value,C Item,C Item In-Kind Value,Dupe Item,Dupe Item In-Kind Value,E Item,E Item In-Kind Value
-          Product Drive,2025-01-01,#{source_name(donations[0])},Test Storage Location,15,2,94.0,It's a fine day for diapers.,7,70.00,0,0.00,0,0.00,8,24.00,0,0.00
-          Manufacturer,2025-01-01,#{source_name(donations[1])},Test Storage Location,1,1,20.0,It's a fine day for diapers.,0,0.00,1,20.00,0,0.00,0,0.00,0,0.00
-          Donation Site,2025-01-01,#{source_name(donations[2])},Test Storage Location,2,1,60.0,It's a fine day for diapers.,0,0.00,0,0.00,2,60.00,0,0.00,0,0.00
-          Misc. Donation,2025-01-01,It's a fine day for...,Test Storage Location,3,1,120.0,It's a fine day for diapers.,0,0.00,0,0.00,0,0.00,0,0.00,3,120.00
-        CSV
-        expect(subject).to eq(csv)
+        expect(subject).to eq(expected_csv("donations_export_case_insensitive_sort.csv"))
       end
     end
   end