diff --git a/app/services/bulk_upload/sales/validator.rb b/app/services/bulk_upload/sales/validator.rb
index 91fa50096..32e9f7533 100644
--- a/app/services/bulk_upload/sales/validator.rb
+++ b/app/services/bulk_upload/sales/validator.rb
@@ -5,6 +5,7 @@ class BulkUpload::Sales::Validator
   attr_reader :bulk_upload, :path
 
   validate :validate_file_not_empty
+  validate :validate_field_numbers_count
   validate :validate_max_columns
   validate :validate_missing_required_headers
   validate :validate_correct_template
@@ -166,6 +167,14 @@ private
 
     if csv_parser.missing_required_headers?
       errors.add :base, I18n.t("activemodel.errors.models.bulk_upload/sales/validator.attributes.base.no_headers", guidance_link: bulk_upload_sales_log_url(id: "guidance", form: { year: bulk_upload.year }, host: ENV["APP_HOST"], anchor: "using-the-bulk-upload-template"))
+    end
+  end
+
+  def validate_field_numbers_count
+    return if halt_validations?
+
+    unless csv_parser.correct_field_count?
+      errors.add(:base, :wrong_field_numbers_count)
       halt_validations!
     end
   end
diff --git a/app/services/bulk_upload/sales/year2023/csv_parser.rb b/app/services/bulk_upload/sales/year2023/csv_parser.rb
index 42b0764d9..036198981 100644
--- a/app/services/bulk_upload/sales/year2023/csv_parser.rb
+++ b/app/services/bulk_upload/sales/year2023/csv_parser.rb
@@ -59,6 +59,10 @@ class BulkUpload::Sales::Year2023::CsvParser
     false
   end
 
+  def correct_field_count?
+    true
+  end
+
 private
 
   def default_field_numbers
diff --git a/app/services/bulk_upload/sales/year2024/csv_parser.rb b/app/services/bulk_upload/sales/year2024/csv_parser.rb
index e53f0ec28..2dc9d38a1 100644
--- a/app/services/bulk_upload/sales/year2024/csv_parser.rb
+++ b/app/services/bulk_upload/sales/year2024/csv_parser.rb
@@ -3,6 +3,7 @@ require "csv"
 class BulkUpload::Sales::Year2024::CsvParser
   include CollectionTimeHelper
 
+  FIELDS = 131
   MAX_COLUMNS = 142
   FORM_YEAR = 2024
 
@@ -59,6 +60,12 @@ class BulkUpload::Sales::Year2024::CsvParser
     !with_headers?
   end
 
+  def correct_field_count?
+    valid_field_numbers_count = field_numbers.count { |f| f != "field_blank" }
+
+    valid_field_numbers_count == FIELDS
+  end
+
 private
 
   def default_field_numbers
diff --git a/spec/services/bulk_upload/sales/year2024/csv_parser_spec.rb b/spec/services/bulk_upload/sales/year2024/csv_parser_spec.rb
index e4391212a..ef90bd834 100644
--- a/spec/services/bulk_upload/sales/year2024/csv_parser_spec.rb
+++ b/spec/services/bulk_upload/sales/year2024/csv_parser_spec.rb
@@ -28,6 +28,10 @@ RSpec.describe BulkUpload::Sales::Year2024::CsvParser do
     it "parses csv correctly" do
       expect(service.row_parsers[0].field_22).to eql(log.uprn)
     end
+
+    it "counts the number of valid field numbers correctly" do
+      expect(service).to be_correct_field_count
+    end
   end
 
   context "when parsing csv with headers in arbitrary order" do