diff --git a/app/services/bulk_upload/lettings/year2026/row_parser.rb b/app/services/bulk_upload/lettings/year2026/row_parser.rb
index 02484aafd..6ecf214a6 100644
--- a/app/services/bulk_upload/lettings/year2026/row_parser.rb
+++ b/app/services/bulk_upload/lettings/year2026/row_parser.rb
@@ -173,6 +173,26 @@ class BulkUpload::Lettings::Year2026::RowParser
 
   ERROR_BASE_KEY = "validations.lettings.2026.bulk_upload".freeze
 
+  CASE_INSENSITIVE_FIELDS = [
+    :field_42, # What is the lead tenant’s age?
+    :field_48, # What is person 2’s age?
+    :field_52, # What is person 3’s age?
+    :field_56, # What is person 4’s age?
+    :field_60, # What is person 5’s age?
+    :field_64, # What is person 6’s age?
+    :field_68, # What is person 7’s age?
+    :field_72, # What is person 8’s age?
+
+    :field_130, # What is the lead tenant's sex?
+    :field_131, # What is person 2's sex?
+    :field_132, # What is person 3's sex?
+    :field_133, # What is person 4's sex?
+    :field_134, # What is person 5's sex?
+    :field_135, # What is person 6's sex?
+    :field_136, # What is person 7's sex?
+    :field_137, # What is person 8's sex?
+  ].freeze
+
   attribute :bulk_upload
   attribute :block_log_creation, :boolean, default: -> { false }
 
@@ -509,6 +529,8 @@ class BulkUpload::Lettings::Year2026::RowParser
 
     return @valid = true if blank_row?
 
+    normalise_case_insensitive_fields
+
     super(:before_log)
     @before_errors = errors.dup
 
@@ -615,6 +637,13 @@ class BulkUpload::Lettings::Year2026::RowParser
 
 private
 
+  def normalise_case_insensitive_fields
+    CASE_INSENSITIVE_FIELDS.each do |field|
+      value = send(field)
+      send("#{field}=", value.upcase) if value.present?
+    end
+  end
+
   def validate_valid_radio_option
     log.attributes.each do |question_id, _v|
       question = log.form.get_question(question_id, log)
diff --git a/app/services/bulk_upload/sales/year2026/row_parser.rb b/app/services/bulk_upload/sales/year2026/row_parser.rb
index adb7cc6a2..7659d0fb6 100644
--- a/app/services/bulk_upload/sales/year2026/row_parser.rb
+++ b/app/services/bulk_upload/sales/year2026/row_parser.rb
@@ -146,6 +146,29 @@ class BulkUpload::Sales::Year2026::RowParser
 
   ERROR_BASE_KEY = "validations.sales.2026.bulk_upload".freeze
 
+  CASE_INSENSITIVE_FIELDS = [
+    :field_28, # Age of buyer 1
+    :field_35, # Age of person 2
+    :field_43, # Age of person 3
+    :field_47, # Age of person 4
+    :field_51, # Age of person 5
+    :field_55, # Age of person 6
+
+    :field_122, # Buyer 1's sex, as registered at birth
+    :field_123, # Buyer/Person 2's sex, as registered at birth
+    :field_124, # Person 3's sex, as registered at birth
+    :field_125, # Person 4's sex, as registered at birth
+    :field_126, # Person 5's sex, as registered at birth
+    :field_127, # Person 6's sex, as registered at birth
+
+    :field_58, # What was buyer 1’s previous tenure?
+    :field_64, # What was buyer 2’s previous tenure?
+
+    :field_75, # What is the total amount the buyers had in savings before they paid any deposit for the property?
+    :field_70, # What is buyer 1’s gross annual income?
+    :field_72, # What is buyer 2’s gross annual income?
+  ].freeze
+
   attribute :bulk_upload
   attribute :block_log_creation, :boolean, default: -> { false }
 
@@ -468,6 +491,8 @@ class BulkUpload::Sales::Year2026::RowParser
 
     return true if blank_row?
 
+    normalise_case_insensitive_fields
+
     super(:before_log)
     @before_errors = errors.dup
 
@@ -540,6 +565,13 @@ class BulkUpload::Sales::Year2026::RowParser
 
 private
 
+  def normalise_case_insensitive_fields
+    CASE_INSENSITIVE_FIELDS.each do |field|
+      value = send(field)
+      send("#{field}=", value.upcase) if value.present?
+    end
+  end
+
   def prevtenbuy2
     case field_64
     when "R"