diff --git a/spec/services/bulk_upload/lettings/year2025/row_parser_spec.rb b/spec/services/bulk_upload/lettings/year2025/row_parser_spec.rb
index 951838e53..6d4bf8b54 100644
--- a/spec/services/bulk_upload/lettings/year2025/row_parser_spec.rb
+++ b/spec/services/bulk_upload/lettings/year2025/row_parser_spec.rb
@@ -541,6 +541,15 @@ RSpec.describe BulkUpload::Lettings::Year2025::RowParser do
               end
             end
           end
+
+          context "and case insensitive fields are set to lowercase" do
+            let(:case_insensitive_fields) { %w[field_42 field_48 field_52 field_56 field_60 field_64 field_68 field_72 field_43 field_49 field_53 field_57 field_61 field_65 field_69 field_73] }
+            let(:attributes) { valid_attributes.merge(case_insensitive_fields.each_with_object({}) { |field, h| h[field.to_sym] = valid_attributes[field.to_sym]&.downcase }) }
+
+            it "is still valid" do
+              expect(parser).to be_valid
+            end
+          end
         end
 
         context "when valid row with valid decimal (integer) field_11" do
diff --git a/spec/services/bulk_upload/lettings/year2026/row_parser_spec.rb b/spec/services/bulk_upload/lettings/year2026/row_parser_spec.rb
index a85bdebbb..35c62b467 100644
--- a/spec/services/bulk_upload/lettings/year2026/row_parser_spec.rb
+++ b/spec/services/bulk_upload/lettings/year2026/row_parser_spec.rb
@@ -151,7 +151,7 @@ RSpec.describe BulkUpload::Lettings::Year2026::RowParser do
             field_15: "1",
 
             field_42: "42",
-            field_48: "41",
+            field_48: "R",
             field_52: "17",
             field_56: "18",
             field_60: "16",
@@ -569,6 +569,15 @@ RSpec.describe BulkUpload::Lettings::Year2026::RowParser do
               end
             end
           end
+
+          context "and case insensitive fields are set to lowercase" do
+            let(:case_insensitive_fields) { %w[field_42 field_48 field_52 field_56 field_60 field_64 field_68 field_72 field_130 field_131 field_132 field_133 field_134 field_135 field_136 field_137] }
+            let(:attributes) { valid_attributes.merge(case_insensitive_fields.each_with_object({}) { |field, h| h[field.to_sym] = valid_attributes[field.to_sym]&.downcase }) }
+
+            it "is still valid" do
+              expect(parser).to be_valid
+            end
+          end
         end
 
         context "when valid row with valid decimal (integer) field_11" do
diff --git a/spec/services/bulk_upload/sales/year2025/row_parser_spec.rb b/spec/services/bulk_upload/sales/year2025/row_parser_spec.rb
index 0074b3712..4b60b1332 100644
--- a/spec/services/bulk_upload/sales/year2025/row_parser_spec.rb
+++ b/spec/services/bulk_upload/sales/year2025/row_parser_spec.rb
@@ -292,6 +292,15 @@ RSpec.describe BulkUpload::Sales::Year2025::RowParser do
           expect(questions.map(&:id).size).to eq(0)
           expect(questions.map(&:id)).to eql([])
         end
+
+        context "and case insensitive fields are set to lowercase" do
+          let(:case_insensitive_fields) { %w[field_28 field_35 field_43 field_47 field_51 field_55 field_29 field_36 field_44 field_48 field_52 field_56 field_58 field_64 field_75 field_70 field_72] }
+          let(:attributes) { valid_attributes.merge(case_insensitive_fields.each_with_object({}) { |field, h| h[field.to_sym] = valid_attributes[field.to_sym]&.downcase }) }
+
+          it "is still valid" do
+            expect(parser).to be_valid
+          end
+        end
       end
 
       describe "#validate_nulls" do
diff --git a/spec/services/bulk_upload/sales/year2026/row_parser_spec.rb b/spec/services/bulk_upload/sales/year2026/row_parser_spec.rb
index f9fb2aa2c..ab5e18f9f 100644
--- a/spec/services/bulk_upload/sales/year2026/row_parser_spec.rb
+++ b/spec/services/bulk_upload/sales/year2026/row_parser_spec.rb
@@ -298,6 +298,15 @@ RSpec.describe BulkUpload::Sales::Year2026::RowParser do
           expect(questions.map(&:id).size).to eq(0)
           expect(questions.map(&:id)).to eql([])
         end
+
+        context "and case insensitive fields are set to lowercase" do
+          let(:case_insensitive_fields) { %w[field_28 field_35 field_43 field_47 field_51 field_55 field_122 field_123 field_124 field_125 field_126 field_127 field_58 field_64 field_75 field_70 field_72] }
+          let(:attributes) { valid_attributes.merge(case_insensitive_fields.each_with_object({}) { |field, h| h[field.to_sym] = valid_attributes[field.to_sym]&.downcase }) }
+
+          it "is still valid" do
+            expect(parser).to be_valid
+          end
+        end
       end
 
       describe "#validate_nulls" do