diff --git a/app/helpers/bulk_upload/sales_log_to_csv.rb b/app/helpers/bulk_upload/sales_log_to_csv.rb
index 1171f481f..8cd695bcf 100644
--- a/app/helpers/bulk_upload/sales_log_to_csv.rb
+++ b/app/helpers/bulk_upload/sales_log_to_csv.rb
@@ -672,7 +672,8 @@ class BulkUpload::SalesLogToCsv
       log.sexrab3,
       log.sexrab4,
       log.sexrab5,
-      log.sexrab6, # 127
+      log.sexrab6,
+      log.buildheightclass, # 128
     ]
   end
 
diff --git a/app/services/bulk_upload/sales/year2026/csv_parser.rb b/app/services/bulk_upload/sales/year2026/csv_parser.rb
index 78e467807..50faaea28 100644
--- a/app/services/bulk_upload/sales/year2026/csv_parser.rb
+++ b/app/services/bulk_upload/sales/year2026/csv_parser.rb
@@ -4,7 +4,7 @@ class BulkUpload::Sales::Year2026::CsvParser
   include CollectionTimeHelper
 
   # TODO: CLDC-4162: Update when 2026 format is known
-  FIELDS = 127
+  FIELDS = 128
   FORM_YEAR = 2026
 
   attr_reader :path
@@ -27,7 +27,7 @@ class BulkUpload::Sales::Year2026::CsvParser
 
   def cols
     # TODO: CLDC-4162: Update when 2026 format is known
-    @cols ||= ("A".."DR").to_a
+    @cols ||= ("A".."DS").to_a
   end
 
   def row_parsers
diff --git a/app/services/bulk_upload/sales/year2026/row_parser.rb b/app/services/bulk_upload/sales/year2026/row_parser.rb
index adb7cc6a2..bb8a86734 100644
--- a/app/services/bulk_upload/sales/year2026/row_parser.rb
+++ b/app/services/bulk_upload/sales/year2026/row_parser.rb
@@ -142,6 +142,7 @@ class BulkUpload::Sales::Year2026::RowParser
     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_128: "What is the building height classification?",
   }.freeze
 
   ERROR_BASE_KEY = "validations.sales.2026.bulk_upload".freeze
@@ -288,6 +289,7 @@ class BulkUpload::Sales::Year2026::RowParser
   attribute :field_125, :string
   attribute :field_126, :string
   attribute :field_127, :string
+  attribute :field_128, :integer
 
   validates :field_1,
             presence: {
@@ -801,6 +803,7 @@ private
       sexrab4: %i[field_125],
       sexrab5: %i[field_126],
       sexrab6: %i[field_127],
+      buildheightclass: %i[field_128],
     }
   end
 
@@ -842,6 +845,7 @@ private
     attributes["sexrab4"] = field_125
     attributes["sexrab5"] = field_126
     attributes["sexrab6"] = field_127
+    attributes["buildheightclass"] = field_128
 
     attributes["relat2"] = relationship_from_is_partner(field_34)
     attributes["relat3"] = relationship_from_is_partner(field_42)
diff --git a/app/services/exports/sales_log_export_constants.rb b/app/services/exports/sales_log_export_constants.rb
index 6dfb2b334..cf6a6e079 100644
--- a/app/services/exports/sales_log_export_constants.rb
+++ b/app/services/exports/sales_log_export_constants.rb
@@ -146,7 +146,7 @@ module Exports::SalesLogExportConstants
     ALL_YEAR_EXPORT_FIELDS << "RELAT#{index}"
   end
 
-  YEAR_2026_EXPORT_FIELDS = Set[]
+  YEAR_2026_EXPORT_FIELDS = Set["BUILDHEIGHTCLASS"]
 
   (1..6).each do |index|
     YEAR_2026_EXPORT_FIELDS << "SEXRAB#{index}"