diff --git a/README.md b/README.md
index 2405f10..a0854b0 100644
--- a/README.md
+++ b/README.md
@@ -62,7 +62,7 @@ amount_code=2,
 document_number=0,
 origin_branch_code=123,
 own_item=16,
-reference_1=0,
+reference_1=nil,
 reference_2=nil,
 shared_item=4,
 transaction_date=Tue, 04 Feb 2016,
diff --git a/lib/norma43/line_parsers/transaction.rb b/lib/norma43/line_parsers/transaction.rb
index 1233433..5ceadb0 100644
--- a/lib/norma43/line_parsers/transaction.rb
+++ b/lib/norma43/line_parsers/transaction.rb
@@ -11,7 +11,7 @@ class Transaction < LineParser
       field :amount_code, 27, :integer
       field :amount, 28..41, :integer
       field :document_number, 42..51, :integer
-      field :reference_1, 52..63, :integer
+      field :reference_1, 52..63
       field :reference_2, 64..79
     end
   end
diff --git a/spec/example1_parse_spec.rb b/spec/example1_parse_spec.rb
index b179b60..31760f5 100644
--- a/spec/example1_parse_spec.rb
+++ b/spec/example1_parse_spec.rb
@@ -58,7 +58,7 @@
               "amount_code"        => 2,
               "amount"             => 1234,
               "document_number"    => 0,
-              "reference_1"        => 0,
+              "reference_1"        => nil,
               "reference_2"        => nil,
             )
           end
diff --git a/spec/example2_parse_spec.rb b/spec/example2_parse_spec.rb
new file mode 100644
index 0000000..fa92b8f
--- /dev/null
+++ b/spec/example2_parse_spec.rb
@@ -0,0 +1,86 @@
+# frozen_string_literal: true
+
+require "norma43"
+
+RSpec.describe Norma43 do
+  describe "parse" do
+    let(:document) do
+      file = File.open(File.join(__dir__, "fixtures/example2.n43"),
+                        encoding: "iso-8859-1")
+      Norma43.parse file
+    end
+
+    it "finds one account" do
+      expect(document.accounts.size).to eq 1
+    end
+
+    describe "first account" do
+      let(:account) { document.accounts.first }
+
+      it "stores expected attributes from AccountStart parser" do
+        expect(account).to have_attributes(
+          "bank_code"             => 81,
+          "branch_code"           => 4797,
+          "account_number"        => 6995216857,
+          "start_date"            => Date.parse("2025-03-17"),
+          "end_date"              => Date.parse("2025-03-17"),
+          "currency_code"         => 978,
+          "information_mode_code" => 3,
+          "abbreviated_name"      => "SEQURA WORLDWIDE S.A.",
+        )
+      end
+
+      it "stores expected attributes from AccountEnd parser" do
+        expect(account).to have_attributes(
+          "balance_code"   => 2,
+          "balance_amount" => 8614571,
+          "debit_entries"  => nil,
+          "debit_amount"   => nil,
+          "credit_entries" => nil,
+          "credit_amount"  => nil,
+        )
+      end
+
+      describe "transactions" do
+        it "finds all transactions" do
+          expect(account.transactions.size).to eq 4
+        end
+
+        describe "first transaction" do
+          let(:transaction) { account.transactions[0] }
+          it "stores expected attributes" do
+            expect(transaction).to have_attributes(
+              "origin_branch_code" => 7013,
+              "transaction_date"   => Date.parse("2025-03-17"),
+              "value_date"         => Date.parse("2025-03-14"),
+              "shared_item"        => 4,
+              "own_item"           => 7,
+              "amount_code"        => 2,
+              "amount"             => 9726,
+              "document_number"    => 6871166755,
+              "reference_1"        => "TRANSFERENCI",
+              "reference_2"        => "A48555633617",
+            )
+          end
+        end
+
+        it "each transaction has 5 additional_items as a maximum" do
+          account.transactions.each do |transaction|
+            expect(transaction.additional_items.size).to be <= 5
+          end
+        end
+
+        describe "first additional item" do
+          let(:additional_item) { account.transactions[0].additional_items[0] }
+          it "stores expected attributes" do
+            expect(additional_item).to have_attributes(
+              "data_code" => 1,
+              "item_1"    => "MARIA NARANJO ENFLOR",
+              "item_2"    => "A48555633617"
+            )
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/spec/fixtures/example2.n43 b/spec/fixtures/example2.n43
new file mode 100644
index 0000000..2d865f7
--- /dev/null
+++ b/spec/fixtures/example2.n43
@@ -0,0 +1,13 @@
+110081479769952168572503172503172000000086145719783SEQURA WORLDWIDE S.A.        
+2201827013250317250314040072000000000097266871166755TRANSFERENCIA48555633617    
+2301MARIA NARANJO ENFLOR                  A48555633617                          
+2302                                      01826874                              
+2201827013250317250317040072000000000074332011157110TRANSFERENCISEQURA          
+2301LAURA MARTINEZ PEREZ                                                       
+2302                                      01822011                              
+2201828510250317250317990512000000000082250000000000BIZUM                       
+2301NAYARA;MARTINEZ RODRIGUEZ             PEDIDO 322200000000                   
+2302                                      15830001                              
+2201828510250317250317990512000000000088940000000000BIZUM                       
+2301DANIEL GARCIA GARCIA                  PEDIDO 322254909000                   
+2302                                      21000900                              
\ No newline at end of file
diff --git a/spec/norma43/line_parsers/transaction_spec.rb b/spec/norma43/line_parsers/transaction_spec.rb
index 7cb8859..ed02af3 100644
--- a/spec/norma43/line_parsers/transaction_spec.rb
+++ b/spec/norma43/line_parsers/transaction_spec.rb
@@ -42,7 +42,7 @@ module LineParsers
       end
 
       it "parses the reference 1" do
-        expect(transaction.reference_1).to eq 0
+        expect(transaction.reference_1).to be_nil
       end
 
       it "parses the reference 2" do