diff --git a/lib/secretariat/invoice.rb b/lib/secretariat/invoice.rb
index 140627b..84b2734 100644
--- a/lib/secretariat/invoice.rb
+++ b/lib/secretariat/invoice.rb
@@ -53,6 +53,9 @@ module Secretariat
     :direct_debit_creditor_id, # BT-90
     :direct_debit_iban, # BT-91,
     :subject_code, # BT-21
+    :type_code, # BT-3, defaults to 380 (commercial invoice)
+    :preceding_invoice_id, # BT-25
+    :preceding_invoice_issue_date, # BT-26
     keyword_init: true
   ) do
 
@@ -212,7 +215,7 @@ def to_xml(version: 1, validate: true)
             if version == 1
               xml['ram'].Name "RECHNUNG"
             end
-            xml['ram'].TypeCode '380' # TODO: make configurable
+            xml['ram'].TypeCode type_code || '380'
             xml['ram'].IssueDateTime do
               xml['udt'].DateTimeString(format: '102') do
                 xml.text(issue_date.strftime("%Y%m%d"))
@@ -351,6 +354,18 @@ def to_xml(version: 1, validate: true)
                 Helpers.currency_element(xml, 'ram', 'TotalPrepaidAmount', paid_amount, currency_code, add_currency: version == 1)
                 Helpers.currency_element(xml, 'ram', 'DuePayableAmount', due_amount, currency_code, add_currency: version == 1)
               end
+              if version == 2 && preceding_invoice_id.present?
+                xml['ram'].InvoiceReferencedDocument do
+                  xml['ram'].IssuerAssignedID preceding_invoice_id
+                  if preceding_invoice_issue_date
+                    xml['ram'].FormattedIssueDateTime do
+                      xml['qdt'].DateTimeString(format: '102') do
+                        xml.text(preceding_invoice_issue_date.strftime("%Y%m%d"))
+                      end
+                    end
+                  end
+                end
+              end
             end
             if version == 1
               line_items.each_with_index do |item, i|
diff --git a/lib/secretariat/trade_party.rb b/lib/secretariat/trade_party.rb
index 8ad0125..d0f6b5e 100644
--- a/lib/secretariat/trade_party.rb
+++ b/lib/secretariat/trade_party.rb
@@ -35,7 +35,8 @@ def to_xml(xml, exclude_tax: false, version: 2)
       xml['ram'].Name name
       if legal_organization.present?
         xml['ram'].SpecifiedLegalOrganization do
-          xml['ram'].ID(schemeID: legal_organization[:scheme_id] || "0002") do
+          scheme_id = legal_organization.fetch(:scheme_id, "0002") # scheme_id: nil omits the scheme (BT-30-1)
+          xml['ram'].ID({ schemeID: scheme_id }.compact) do
             xml.text(legal_organization[:id])
           end
         end
diff --git a/test/invoice_test.rb b/test/invoice_test.rb
index 8af2c76..cdd3739 100644
--- a/test/invoice_test.rb
+++ b/test/invoice_test.rb
@@ -861,6 +861,50 @@ def test_fr_invoice
       assert_match(%r{<ram:SpecifiedLegalOrganization>\s*<ram:ID schemeID="0002">304755032</ram:ID>\s*</ram:SpecifiedLegalOrganization>}, xml)
     end
 
+    def test_type_code_defaults_to_commercial_invoice
+      xml = make_de_invoice.to_xml(version: 2)
+      assert_match(%r{<ram:TypeCode>380</ram:TypeCode>}, xml)
+    end
+
+    def test_credit_note_with_preceding_invoice
+      invoice = make_eu_invoice
+      invoice.type_code = '381'
+      invoice.preceding_invoice_id = 'R-2026-0042'
+      invoice.preceding_invoice_issue_date = Date.new(2026, 10, 1)
+      xml = invoice.to_xml(version: 2)
+
+      assert_match(%r{<ram:TypeCode>381</ram:TypeCode>}, xml)
+      assert_match(%r{</ram:SpecifiedTradeSettlementHeaderMonetarySummation>\s*<ram:InvoiceReferencedDocument>\s*<ram:IssuerAssignedID>R-2026-0042</ram:IssuerAssignedID>\s*<ram:FormattedIssueDateTime>\s*<qdt:DateTimeString format="102">20261001</qdt:DateTimeString>\s*</ram:FormattedIssueDateTime>\s*</ram:InvoiceReferencedDocument>}, xml)
+      assert_equal [], Validator.new(xml, version: 2).validate_against_schematron
+    end
+
+    def test_preceding_invoice_without_issue_date
+      invoice = make_de_invoice
+      invoice.preceding_invoice_id = 'R-2026-0042'
+      xml = invoice.to_xml(version: 2)
+
+      assert_match(%r{<ram:InvoiceReferencedDocument>\s*<ram:IssuerAssignedID>R-2026-0042</ram:IssuerAssignedID>\s*</ram:InvoiceReferencedDocument>}, xml)
+    end
+
+    def test_no_preceding_invoice_by_default
+      xml = make_de_invoice.to_xml(version: 2)
+      refute_match(/InvoiceReferencedDocument/, xml)
+    end
+
+    def test_legal_organization_without_scheme
+      invoice = make_fr_invoice
+      invoice.seller.legal_organization = { id: 'HRB 12345', scheme_id: nil }
+      xml = invoice.to_xml(version: 2)
+      assert_match(%r{<ram:SpecifiedLegalOrganization>\s*<ram:ID>HRB 12345</ram:ID>\s*</ram:SpecifiedLegalOrganization>}, xml)
+    end
+
+    def test_legal_organization_scheme_defaults_to_sirene
+      invoice = make_fr_invoice
+      invoice.seller.legal_organization = { id: '304755032' }
+      xml = invoice.to_xml(version: 2)
+      assert_match(%r{<ram:ID schemeID="0002">304755032</ram:ID>}, xml)
+    end
+
     def test_invoice_with_quantity_causing_sub_cent_amounts
       errors = []