diff --git a/app/models/champ.rb b/app/models/champ.rb
index 02f82d25a..fb7bf56e9 100644
--- a/app/models/champ.rb
+++ b/app/models/champ.rb
@@ -99,11 +99,11 @@ class Champ < ApplicationRecord
   end
 
   def mandatory_blank?
-    mandatory? && blank?
+    type_de_champ.mandatory_blank?(self)
   end
 
   def blank?
-    value.blank?
+    type_de_champ.champ_blank?(self)
   end
 
   def search_terms
diff --git a/app/models/champs/carte_champ.rb b/app/models/champs/carte_champ.rb
index 49c4e90ac..aa7e1560f 100644
--- a/app/models/champs/carte_champ.rb
+++ b/app/models/champs/carte_champ.rb
@@ -85,10 +85,6 @@ class Champs::CarteChamp < Champ
     end
   end
 
-  def blank?
-    geo_areas.blank?
-  end
-
   private
 
   def selection_utilisateur_legacy_geometry
diff --git a/app/models/champs/checkbox_champ.rb b/app/models/champs/checkbox_champ.rb
index 2610b6bb0..111eaeb00 100644
--- a/app/models/champs/checkbox_champ.rb
+++ b/app/models/champs/checkbox_champ.rb
@@ -1,10 +1,6 @@
 # frozen_string_literal: true
 
 class Champs::CheckboxChamp < Champs::BooleanChamp
-  def mandatory_blank?
-    mandatory? && (blank? || !true?)
-  end
-
   def legend_label?
     false
   end
@@ -13,11 +9,6 @@ class Champs::CheckboxChamp < Champs::BooleanChamp
     [[I18n.t('activerecord.attributes.type_de_champ.type_champs.checkbox_true'), true], [I18n.t('activerecord.attributes.type_de_champ.type_champs.checkbox_false'), false]]
   end
 
-  # TODO remove when normalize_checkbox_values is over
-  def true?
-    value_with_legacy == TRUE_VALUE
-  end
-
   def html_label?
     false
   end
@@ -25,11 +16,4 @@ class Champs::CheckboxChamp < Champs::BooleanChamp
   def single_checkbox?
     true
   end
-
-  private
-
-  # TODO remove when normalize_checkbox_values is over
-  def value_with_legacy
-    value == 'on' ? TRUE_VALUE : value
-  end
 end
diff --git a/app/models/champs/cnaf_champ.rb b/app/models/champs/cnaf_champ.rb
index abbca23d1..c0cdc9383 100644
--- a/app/models/champs/cnaf_champ.rb
+++ b/app/models/champs/cnaf_champ.rb
@@ -8,10 +8,6 @@ class Champs::CnafChamp < Champs::TextChamp
 
   store_accessor :value_json, :numero_allocataire, :code_postal
 
-  def blank?
-    external_id.nil?
-  end
-
   def fetch_external_data?
     true
   end
diff --git a/app/models/champs/cojo_champ.rb b/app/models/champs/cojo_champ.rb
index 14dc41816..a770521eb 100644
--- a/app/models/champs/cojo_champ.rb
+++ b/app/models/champs/cojo_champ.rb
@@ -20,10 +20,6 @@ class Champs::COJOChamp < Champ
     accreditation_success == false
   end
 
-  def blank?
-    accreditation_success != true
-  end
-
   def fetch_external_data?
     true
   end
diff --git a/app/models/champs/dgfip_champ.rb b/app/models/champs/dgfip_champ.rb
index 3e959659f..c64e55b9a 100644
--- a/app/models/champs/dgfip_champ.rb
+++ b/app/models/champs/dgfip_champ.rb
@@ -7,10 +7,6 @@ class Champs::DgfipChamp < Champs::TextChamp
 
   store_accessor :value_json, :numero_fiscal, :reference_avis
 
-  def blank?
-    external_id.nil?
-  end
-
   def fetch_external_data?
     true
   end
diff --git a/app/models/champs/linked_drop_down_list_champ.rb b/app/models/champs/linked_drop_down_list_champ.rb
index 7bb349476..65e6c576c 100644
--- a/app/models/champs/linked_drop_down_list_champ.rb
+++ b/app/models/champs/linked_drop_down_list_champ.rb
@@ -35,11 +35,6 @@ class Champs::LinkedDropDownListChamp < Champ
     :primary_value
   end
 
-  def blank?
-    primary_value.blank? ||
-      (has_secondary_options_for_primary? && secondary_value.blank?)
-  end
-
   def search_terms
     [primary_value, secondary_value]
   end
diff --git a/app/models/champs/mesri_champ.rb b/app/models/champs/mesri_champ.rb
index eab2e5a44..2d8bc2114 100644
--- a/app/models/champs/mesri_champ.rb
+++ b/app/models/champs/mesri_champ.rb
@@ -4,10 +4,6 @@ class Champs::MesriChamp < Champs::TextChamp
   # see https://github.com/betagouv/api-particulier/blob/master/src/presentation/middlewares/mesri-input-validation.middleware.ts
   store_accessor :value_json, :ine
 
-  def blank?
-    external_id.nil?
-  end
-
   def fetch_external_data?
     true
   end
diff --git a/app/models/champs/multiple_drop_down_list_champ.rb b/app/models/champs/multiple_drop_down_list_champ.rb
index 8ea0bec25..2bc715a06 100644
--- a/app/models/champs/multiple_drop_down_list_champ.rb
+++ b/app/models/champs/multiple_drop_down_list_champ.rb
@@ -29,10 +29,6 @@ class Champs::MultipleDropDownListChamp < Champ
     render_as_checkboxes?
   end
 
-  def blank?
-    selected_options.blank?
-  end
-
   def in?(options)
     (selected_options - options).size != selected_options.size
   end
diff --git a/app/models/champs/pays_champ.rb b/app/models/champs/pays_champ.rb
index bcd1827b6..a1a6e3d37 100644
--- a/app/models/champs/pays_champ.rb
+++ b/app/models/champs/pays_champ.rb
@@ -35,10 +35,6 @@ class Champs::PaysChamp < Champs::TextChamp
     end
   end
 
-  def blank?
-    value.blank? && external_id.blank?
-  end
-
   def code
     external_id || APIGeoService.country_code(value)
   end
diff --git a/app/models/champs/piece_justificative_champ.rb b/app/models/champs/piece_justificative_champ.rb
index 5d64239b2..b282aee35 100644
--- a/app/models/champs/piece_justificative_champ.rb
+++ b/app/models/champs/piece_justificative_champ.rb
@@ -21,12 +21,4 @@ class Champs::PieceJustificativeChamp < Champ
   def search_terms
     # We don’t know how to search inside documents yet
   end
-
-  def mandatory_blank?
-    mandatory? && !piece_justificative_file.attached?
-  end
-
-  def blank?
-    piece_justificative_file.blank?
-  end
 end
diff --git a/app/models/champs/pole_emploi_champ.rb b/app/models/champs/pole_emploi_champ.rb
index 374debacd..5a5d917f4 100644
--- a/app/models/champs/pole_emploi_champ.rb
+++ b/app/models/champs/pole_emploi_champ.rb
@@ -4,10 +4,6 @@ class Champs::PoleEmploiChamp < Champs::TextChamp
   # see https://github.com/betagouv/api-particulier/blob/master/src/presentation/middlewares/pole-emploi-input-validation.middleware.ts
   store_accessor :value_json, :identifiant
 
-  def blank?
-    external_id.nil?
-  end
-
   def fetch_external_data?
     true
   end
diff --git a/app/models/champs/repetition_champ.rb b/app/models/champs/repetition_champ.rb
index 4bb65c484..e94bbf518 100644
--- a/app/models/champs/repetition_champ.rb
+++ b/app/models/champs/repetition_champ.rb
@@ -23,10 +23,6 @@ class Champs::RepetitionChamp < Champ
     rows.last&.first&.focusable_input_id
   end
 
-  def blank?
-    row_ids.empty?
-  end
-
   def search_terms
     # The user cannot enter any information here so it doesn’t make much sense to search
   end
diff --git a/app/models/champs/rnf_champ.rb b/app/models/champs/rnf_champ.rb
index 56850c55f..3b9a8fa7a 100644
--- a/app/models/champs/rnf_champ.rb
+++ b/app/models/champs/rnf_champ.rb
@@ -27,10 +27,6 @@ class Champs::RNFChamp < Champ
     true
   end
 
-  def blank?
-    rnf_id.blank?
-  end
-
   def code_departement
     address.present? && address['departmentCode']
   end
diff --git a/app/models/champs/siret_champ.rb b/app/models/champs/siret_champ.rb
index bb48c77d9..f124d218d 100644
--- a/app/models/champs/siret_champ.rb
+++ b/app/models/champs/siret_champ.rb
@@ -6,8 +6,4 @@ class Champs::SiretChamp < Champ
   def search_terms
     etablissement.present? ? etablissement.search_terms : [value]
   end
-
-  def mandatory_blank?
-    mandatory? && Siret.new(siret: value).invalid?
-  end
 end
diff --git a/app/models/champs/titre_identite_champ.rb b/app/models/champs/titre_identite_champ.rb
index a58cdcdbd..790259f7c 100644
--- a/app/models/champs/titre_identite_champ.rb
+++ b/app/models/champs/titre_identite_champ.rb
@@ -16,12 +16,4 @@ class Champs::TitreIdentiteChamp < Champ
   def search_terms
     # We don’t know how to search inside documents yet
   end
-
-  def mandatory_blank?
-    mandatory? && !piece_justificative_file.attached?
-  end
-
-  def blank?
-    piece_justificative_file.blank?
-  end
 end
diff --git a/app/models/type_de_champ.rb b/app/models/type_de_champ.rb
index 79bfa7088..b979fdf45 100644
--- a/app/models/type_de_champ.rb
+++ b/app/models/type_de_champ.rb
@@ -709,7 +709,7 @@ class TypeDeChamp < ApplicationRecord
   end
 
   def champ_value(champ)
-    if use_default_value?(champ)
+    if champ_blank?(champ)
       dynamic_type.champ_default_value
     else
       dynamic_type.champ_value(champ)
@@ -717,7 +717,7 @@ class TypeDeChamp < ApplicationRecord
   end
 
   def champ_value_for_api(champ, version: 2)
-    if use_default_value?(champ)
+    if champ_blank?(champ)
       dynamic_type.champ_default_api_value(version)
     else
       dynamic_type.champ_value_for_api(champ, version:)
@@ -725,7 +725,7 @@ class TypeDeChamp < ApplicationRecord
   end
 
   def champ_value_for_export(champ, path = :value)
-    if use_default_value?(champ)
+    if champ_blank?(champ)
       dynamic_type.champ_default_export_value(path)
     else
       dynamic_type.champ_value_for_export(champ, path)
@@ -733,13 +733,35 @@ class TypeDeChamp < ApplicationRecord
   end
 
   def champ_value_for_tag(champ, path = :value)
-    if use_default_value?(champ)
+    if champ_blank?(champ)
       ''
     else
       dynamic_type.champ_value_for_tag(champ, path)
     end
   end
 
+  def champ_blank?(champ)
+    # no champ
+    return true if champ.nil?
+    # type de champ on the revision changed
+    if champ.last_write_type_champ == type_champ || castable_on_change?(champ.last_write_type_champ, type_champ)
+      dynamic_type.champ_blank?(champ)
+    else
+      true
+    end
+  end
+
+  def mandatory_blank?(champ)
+    # no champ
+    return true if champ.nil?
+    # type de champ on the revision changed
+    if champ.last_write_type_champ == type_champ || castable_on_change?(champ.last_write_type_champ, type_champ)
+      mandatory? && dynamic_type.champ_blank_or_invalid?(champ)
+    else
+      true
+    end
+  end
+
   def html_id(row_id = nil)
     "champ-#{public_id(row_id)}"
   end
@@ -758,24 +780,12 @@ class TypeDeChamp < ApplicationRecord
 
   private
 
-  def use_default_value?(champ)
-    # no champ
-    return true if champ.nil?
-    # type de champ on the revision changed
-    if champ.last_write_type_champ != type_champ
-      return !castable_on_change?(champ.last_write_type_champ, type_champ)
-    end
-    # special case for linked drop down champ – it's blank implementation is not what you think
-    return champ.value.blank? if type_champ == TypeDeChamp.type_champs.fetch(:linked_drop_down_list)
-    champ.blank?
-  end
-
   def castable_on_change?(from_type, to_type)
     case [from_type, to_type]
     when ['integer_number', 'decimal_number'], # recast numbers automatically
       ['decimal_number', 'integer_number'], # may lose some data, but who cares ?
       ['text', 'textarea'], # allow short text to long text
-      # ['drop_down_list', 'multiple_drop_down_list'], # single list can become multi
+      ['drop_down_list', 'multiple_drop_down_list'], # single list can become multi
       ['date', 'datetime'], # date <=> datetime
       ['datetime', 'date'] # may lose some data, but who cares ?
       true
diff --git a/app/models/types_de_champ/carte_type_de_champ.rb b/app/models/types_de_champ/carte_type_de_champ.rb
index 01cbd2a20..5903c5a2c 100644
--- a/app/models/types_de_champ/carte_type_de_champ.rb
+++ b/app/models/types_de_champ/carte_type_de_champ.rb
@@ -28,6 +28,8 @@ class TypesDeChamp::CarteTypeDeChamp < TypesDeChamp::TypeDeChampBase
     champ.geo_areas.map(&:label).join("\n")
   end
 
+  def champ_blank?(champ) = champ.geo_areas.blank?
+
   def columns(procedure_id:, displayable: true, prefix: nil)
     []
   end
diff --git a/app/models/types_de_champ/checkbox_type_de_champ.rb b/app/models/types_de_champ/checkbox_type_de_champ.rb
index 338352c22..9cf47a847 100644
--- a/app/models/types_de_champ/checkbox_type_de_champ.rb
+++ b/app/models/types_de_champ/checkbox_type_de_champ.rb
@@ -12,21 +12,17 @@ class TypesDeChamp::CheckboxTypeDeChamp < TypesDeChamp::TypeDeChampBase
   end
 
   def champ_value(champ)
-    champ.true? ? 'Oui' : 'Non'
-  end
-
-  def champ_value_for_tag(champ, path = :value)
-    champ_value(champ)
+    champ_value_true?(champ) ? 'Oui' : 'Non'
   end
 
   def champ_value_for_export(champ, path = :value)
-    champ.true? ? 'on' : 'off'
+    champ_value_true?(champ) ? 'on' : 'off'
   end
 
   def champ_value_for_api(champ, version: 2)
     case version
     when 2
-      champ.true? ? 'true' : 'false'
+      champ_value_true?(champ).to_s
     else
       super
     end
@@ -48,4 +44,10 @@ class TypesDeChamp::CheckboxTypeDeChamp < TypesDeChamp::TypeDeChampBase
       nil
     end
   end
+
+  def champ_blank_or_invalid?(champ) = !champ_value_true?(champ)
+
+  private
+
+  def champ_value_true?(champ) = champ.value == 'true'
 end
diff --git a/app/models/types_de_champ/cnaf_type_de_champ.rb b/app/models/types_de_champ/cnaf_type_de_champ.rb
index 70dafb9a6..9a6d1b58e 100644
--- a/app/models/types_de_champ/cnaf_type_de_champ.rb
+++ b/app/models/types_de_champ/cnaf_type_de_champ.rb
@@ -4,4 +4,6 @@ class TypesDeChamp::CnafTypeDeChamp < TypesDeChamp::TextTypeDeChamp
   def estimated_fill_duration(revision)
     FILL_DURATION_MEDIUM
   end
+
+  def champ_blank?(champ) = champ.external_id.blank?
 end
diff --git a/app/models/types_de_champ/cojo_type_de_champ.rb b/app/models/types_de_champ/cojo_type_de_champ.rb
index d596d6a7c..5d65a80ff 100644
--- a/app/models/types_de_champ/cojo_type_de_champ.rb
+++ b/app/models/types_de_champ/cojo_type_de_champ.rb
@@ -4,4 +4,6 @@ class TypesDeChamp::COJOTypeDeChamp < TypesDeChamp::TextTypeDeChamp
   def champ_value(champ)
     "#{champ.accreditation_number} – #{champ.accreditation_birthdate}"
   end
+
+  def champ_blank?(champ) = champ.accreditation_success != true
 end
diff --git a/app/models/types_de_champ/dgfip_type_de_champ.rb b/app/models/types_de_champ/dgfip_type_de_champ.rb
index ecc107530..7c20a7c7d 100644
--- a/app/models/types_de_champ/dgfip_type_de_champ.rb
+++ b/app/models/types_de_champ/dgfip_type_de_champ.rb
@@ -4,4 +4,6 @@ class TypesDeChamp::DgfipTypeDeChamp < TypesDeChamp::TextTypeDeChamp
   def estimated_fill_duration(revision)
     FILL_DURATION_MEDIUM
   end
+
+  def champ_blank?(champ) = champ.external_id.blank?
 end
diff --git a/app/models/types_de_champ/linked_drop_down_list_type_de_champ.rb b/app/models/types_de_champ/linked_drop_down_list_type_de_champ.rb
index 44333e0b2..577936c9b 100644
--- a/app/models/types_de_champ/linked_drop_down_list_type_de_champ.rb
+++ b/app/models/types_de_champ/linked_drop_down_list_type_de_champ.rb
@@ -11,11 +11,6 @@ class TypesDeChamp::LinkedDropDownListTypeDeChamp < TypesDeChamp::TypeDeChampBas
     [[path[:libelle], path[:path]]]
   end
 
-  def add_blank_option_when_not_mandatory(options)
-    return options if mandatory
-    options.unshift('')
-  end
-
   def primary_options
     primary_options = unpack_options.map(&:first)
     if primary_options.present?
@@ -33,15 +28,15 @@ class TypesDeChamp::LinkedDropDownListTypeDeChamp < TypesDeChamp::TypeDeChampBas
   end
 
   def champ_value(champ)
-    [champ.primary_value, champ.secondary_value].filter(&:present?).join(' / ')
+    [primary_value(champ), secondary_value(champ)].filter(&:present?).join(' / ')
   end
 
   def champ_value_for_tag(champ, path = :value)
     case path
     when :primary
-      champ.primary_value
+      primary_value(champ)
     when :secondary
-      champ.secondary_value
+      secondary_value(champ)
     when :value
       champ_value(champ)
     end
@@ -50,23 +45,32 @@ class TypesDeChamp::LinkedDropDownListTypeDeChamp < TypesDeChamp::TypeDeChampBas
   def champ_value_for_export(champ, path = :value)
     case path
     when :primary
-      champ.primary_value
+      primary_value(champ)
     when :secondary
-      champ.secondary_value
+      secondary_value(champ)
     when :value
-      "#{champ.primary_value || ''};#{champ.secondary_value || ''}"
+      "#{primary_value(champ) || ''};#{secondary_value(champ) || ''}"
     end
   end
 
   def champ_value_for_api(champ, version: 2)
     case version
     when 1
-      { primary: champ.primary_value, secondary: champ.secondary_value }
+      { primary: primary_value(champ), secondary: secondary_value(champ) }
     else
       super
     end
   end
 
+  def champ_blank?(champ)
+    primary_value(champ).blank? && secondary_value(champ).blank?
+  end
+
+  def champ_blank_or_invalid?(champ)
+    primary_value(champ).blank? ||
+      (has_secondary_options_for_primary?(champ) && secondary_value(champ).blank?)
+  end
+
   def columns(procedure_id:, displayable: true, prefix: nil)
     [
       Columns::LinkedDropDownColumn.new(
@@ -101,6 +105,19 @@ class TypesDeChamp::LinkedDropDownListTypeDeChamp < TypesDeChamp::TypeDeChampBas
 
   private
 
+  def add_blank_option_when_not_mandatory(options)
+    return options if mandatory
+    options.unshift('')
+  end
+
+  def primary_value(champ) = unpack_value(champ.value, 0)
+  def secondary_value(champ) = unpack_value(champ.value, 1)
+  def unpack_value(value, index) = value&.then { JSON.parse(_1)[index] rescue nil }
+
+  def has_secondary_options_for_primary?(champ)
+    primary_value(champ).present? && secondary_options[primary_value(champ)]&.any?(&:present?)
+  end
+
   def paths
     paths = super
     paths.push({
diff --git a/app/models/types_de_champ/mesri_type_de_champ.rb b/app/models/types_de_champ/mesri_type_de_champ.rb
index 3d947c0a1..ff0584800 100644
--- a/app/models/types_de_champ/mesri_type_de_champ.rb
+++ b/app/models/types_de_champ/mesri_type_de_champ.rb
@@ -4,4 +4,6 @@ class TypesDeChamp::MesriTypeDeChamp < TypesDeChamp::TextTypeDeChamp
   def estimated_fill_duration(revision)
     FILL_DURATION_MEDIUM
   end
+
+  def champ_blank?(champ) = champ.external_id.blank?
 end
diff --git a/app/models/types_de_champ/multiple_drop_down_list_type_de_champ.rb b/app/models/types_de_champ/multiple_drop_down_list_type_de_champ.rb
index 3a0d3c2c6..e14bd6cfa 100644
--- a/app/models/types_de_champ/multiple_drop_down_list_type_de_champ.rb
+++ b/app/models/types_de_champ/multiple_drop_down_list_type_de_champ.rb
@@ -2,14 +2,30 @@
 
 class TypesDeChamp::MultipleDropDownListTypeDeChamp < TypesDeChamp::TypeDeChampBase
   def champ_value(champ)
-    champ.selected_options.join(', ')
+    selected_options(champ).join(', ')
   end
 
   def champ_value_for_tag(champ, path = :value)
-    ChampPresentations::MultipleDropDownListPresentation.new(champ.selected_options)
+    ChampPresentations::MultipleDropDownListPresentation.new(selected_options(champ))
   end
 
   def champ_value_for_export(champ, path = :value)
-    champ.selected_options.join(', ')
+    champ_value(champ)
+  end
+
+  def champ_blank?(champ) = selected_options(champ).blank?
+
+  private
+
+  def selected_options(champ)
+    return [] if champ.value.blank?
+
+    if champ.last_write_type_champ == TypeDeChamp.type_champs.fetch(:drop_down_list)
+      [champ.value]
+    else
+      JSON.parse(champ.value)
+    end
+  rescue JSON::ParserError
+    []
   end
 end
diff --git a/app/models/types_de_champ/pays_type_de_champ.rb b/app/models/types_de_champ/pays_type_de_champ.rb
index 54aa9de9b..40d60e1b3 100644
--- a/app/models/types_de_champ/pays_type_de_champ.rb
+++ b/app/models/types_de_champ/pays_type_de_champ.rb
@@ -23,6 +23,10 @@ class TypesDeChamp::PaysTypeDeChamp < TypesDeChamp::TextTypeDeChamp
     end
   end
 
+  def champ_blank?(champ)
+    champ.value.blank? && champ.external_id.blank?
+  end
+
   private
 
   def paths
diff --git a/app/models/types_de_champ/piece_justificative_type_de_champ.rb b/app/models/types_de_champ/piece_justificative_type_de_champ.rb
index 2c68ef035..5ddd1bef6 100644
--- a/app/models/types_de_champ/piece_justificative_type_de_champ.rb
+++ b/app/models/types_de_champ/piece_justificative_type_de_champ.rb
@@ -23,6 +23,8 @@ class TypesDeChamp::PieceJustificativeTypeDeChamp < TypesDeChamp::TypeDeChampBas
     end
   end
 
+  def champ_blank?(champ) = champ.piece_justificative_file.blank?
+
   def columns(procedure_id:, displayable: true, prefix: nil)
     []
   end
diff --git a/app/models/types_de_champ/pole_emploi_type_de_champ.rb b/app/models/types_de_champ/pole_emploi_type_de_champ.rb
index db6271939..e41113f6a 100644
--- a/app/models/types_de_champ/pole_emploi_type_de_champ.rb
+++ b/app/models/types_de_champ/pole_emploi_type_de_champ.rb
@@ -4,4 +4,6 @@ class TypesDeChamp::PoleEmploiTypeDeChamp < TypesDeChamp::TextTypeDeChamp
   def estimated_fill_duration(revision)
     FILL_DURATION_MEDIUM
   end
+
+  def champ_blank?(champ) = champ.external_id.blank?
 end
diff --git a/app/models/types_de_champ/repetition_type_de_champ.rb b/app/models/types_de_champ/repetition_type_de_champ.rb
index b1325472f..28db1512d 100644
--- a/app/models/types_de_champ/repetition_type_de_champ.rb
+++ b/app/models/types_de_champ/repetition_type_de_champ.rb
@@ -3,9 +3,7 @@
 class TypesDeChamp::RepetitionTypeDeChamp < TypesDeChamp::TypeDeChampBase
   def champ_value_for_tag(champ, path = :value)
     return nil if path != :value
-    return champ_default_value if champ.rows.blank?
-
-    ChampPresentations::RepetitionPresentation.new(champ.libelle, champ.rows)
+    ChampPresentations::RepetitionPresentation.new(libelle, champ.dossier.project_rows_for(@type_de_champ))
   end
 
   def estimated_fill_duration(revision)
@@ -32,4 +30,6 @@ class TypesDeChamp::RepetitionTypeDeChamp < TypesDeChamp::TypeDeChampBase
       .all_revisions_types_de_champ(parent: @type_de_champ)
       .flat_map { _1.columns(procedure_id:, displayable: false, prefix: libelle) }
   end
+
+  def champ_blank?(champ) = champ.dossier.repetition_row_ids(@type_de_champ).blank?
 end
diff --git a/app/models/types_de_champ/rnf_type_de_champ.rb b/app/models/types_de_champ/rnf_type_de_champ.rb
index b93ae872e..aacad9bae 100644
--- a/app/models/types_de_champ/rnf_type_de_champ.rb
+++ b/app/models/types_de_champ/rnf_type_de_champ.rb
@@ -33,6 +33,8 @@ class TypesDeChamp::RNFTypeDeChamp < TypesDeChamp::TextTypeDeChamp
     end
   end
 
+  def champ_blank?(champ) = champ.external_id.blank?
+
   private
 
   def paths
diff --git a/app/models/types_de_champ/siret_type_de_champ.rb b/app/models/types_de_champ/siret_type_de_champ.rb
index b7ed7732b..a75a091d2 100644
--- a/app/models/types_de_champ/siret_type_de_champ.rb
+++ b/app/models/types_de_champ/siret_type_de_champ.rb
@@ -6,4 +6,6 @@ class TypesDeChamp::SiretTypeDeChamp < TypesDeChamp::TypeDeChampBase
   def estimated_fill_duration(revision)
     FILL_DURATION_MEDIUM
   end
+
+  def champ_blank_or_invalid?(champ) = Siret.new(siret: champ.value).invalid?
 end
diff --git a/app/models/types_de_champ/titre_identite_type_de_champ.rb b/app/models/types_de_champ/titre_identite_type_de_champ.rb
index 617603c10..0cbd1e906 100644
--- a/app/models/types_de_champ/titre_identite_type_de_champ.rb
+++ b/app/models/types_de_champ/titre_identite_type_de_champ.rb
@@ -22,6 +22,8 @@ class TypesDeChamp::TitreIdentiteTypeDeChamp < TypesDeChamp::TypeDeChampBase
     "absent"
   end
 
+  def champ_blank?(champ) = champ.piece_justificative_file.blank?
+
   def columns(procedure_id:, displayable: nil, prefix: nil)
     [
       Columns::TitreIdentiteColumn.new(
diff --git a/app/models/types_de_champ/type_de_champ_base.rb b/app/models/types_de_champ/type_de_champ_base.rb
index e4babe257..336193dea 100644
--- a/app/models/types_de_champ/type_de_champ_base.rb
+++ b/app/models/types_de_champ/type_de_champ_base.rb
@@ -92,6 +92,9 @@ class TypesDeChamp::TypeDeChampBase
     end
   end
 
+  def champ_blank?(champ) = champ.value.blank?
+  def champ_blank_or_invalid?(champ) = champ_blank?(champ)
+
   def columns(procedure_id:, displayable: true, prefix: nil)
     if fillable?
       [
diff --git a/app/models/types_de_champ/yes_no_type_de_champ.rb b/app/models/types_de_champ/yes_no_type_de_champ.rb
index 947e31d79..1821ce4cb 100644
--- a/app/models/types_de_champ/yes_no_type_de_champ.rb
+++ b/app/models/types_de_champ/yes_no_type_de_champ.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class TypesDeChamp::YesNoTypeDeChamp < TypesDeChamp::CheckboxTypeDeChamp
+class TypesDeChamp::YesNoTypeDeChamp < TypesDeChamp::TypeDeChampBase
   def filter_to_human(filter_value)
     if filter_value == "true"
       I18n.t('activerecord.attributes.type_de_champ.type_champs.yes_no_true')
@@ -12,21 +12,17 @@ class TypesDeChamp::YesNoTypeDeChamp < TypesDeChamp::CheckboxTypeDeChamp
   end
 
   def champ_value(champ)
-    champ_formatted_value(champ)
-  end
-
-  def champ_value_for_tag(champ, path = :value)
-    champ_formatted_value(champ)
+    champ_value_true?(champ) ? 'Oui' : 'Non'
   end
 
   def champ_value_for_export(champ, path = :value)
-    champ_formatted_value(champ)
+    champ_value_true?(champ) ? 'Oui' : 'Non'
   end
 
   def champ_value_for_api(champ, version: 2)
     case version
     when 2
-      champ.true? ? 'true' : 'false'
+      champ_value_true?(champ).to_s
     else
       super
     end
@@ -42,7 +38,7 @@ class TypesDeChamp::YesNoTypeDeChamp < TypesDeChamp::CheckboxTypeDeChamp
 
   private
 
-  def champ_formatted_value(champ)
-    champ.true? ? 'Oui' : 'Non'
+  def champ_value_true?(champ)
+    champ.value == 'true'
   end
 end
diff --git a/spec/models/champ_spec.rb b/spec/models/champ_spec.rb
index 3c2368f95..dd4598017 100644
--- a/spec/models/champ_spec.rb
+++ b/spec/models/champ_spec.rb
@@ -5,7 +5,7 @@ describe Champ do
 
   describe 'mandatory_blank?' do
     let(:type_de_champ) { build(:type_de_champ, mandatory: mandatory) }
-    let(:champ) { Champ.new(value: value) }
+    let(:champ) { Champs::TextChamp.new(value: value) }
     let(:value) { '' }
     let(:mandatory) { true }
 
diff --git a/spec/models/champs/checkbox_champ_spec.rb b/spec/models/champs/checkbox_champ_spec.rb
index 6c93e3176..720ae1ec4 100644
--- a/spec/models/champs/checkbox_champ_spec.rb
+++ b/spec/models/champs/checkbox_champ_spec.rb
@@ -9,12 +9,6 @@ describe Champs::CheckboxChamp do
   describe '#true?' do
     subject { boolean_champ.true? }
 
-    context "when the checkbox value is 'on'" do
-      let(:value) { 'on' }
-
-      it { is_expected.to eq(true) }
-    end
-
     context "when the checkbox value is 'off'" do
       let(:value) { 'off' }
 
diff --git a/spec/models/type_de_champ_spec.rb b/spec/models/type_de_champ_spec.rb
index a0481a31e..605ddb961 100644
--- a/spec/models/type_de_champ_spec.rb
+++ b/spec/models/type_de_champ_spec.rb
@@ -413,4 +413,66 @@ describe TypeDeChamp do
       end
     end
   end
+
+  describe 'champ_value with cast' do
+    let(:procedure) { create(:procedure, types_de_champ_public: [{ type: type_champ }]) }
+    let(:dossier) { create(:dossier, procedure:) }
+    let(:type_champ) { :text }
+    let(:last_write_type_champ) { :text }
+    let(:champ_value) { 'hello' }
+    let(:champ_type) { TypeDeChamp.type_champ_to_champ_class_name(last_write_type_champ.to_s) }
+    let(:type_de_champ) { procedure.active_revision.types_de_champ.first }
+    let(:champ) { dossier.champs.first }
+
+    subject { champ.update_columns(type: champ_type, value: champ_value); type_de_champ.champ_value(champ) }
+
+    it { expect(subject).to eq('hello') }
+
+    context 'text -> integer_number' do
+      let(:last_write_type_champ) { :text }
+      let(:type_champ) { :integer_number }
+
+      it { expect(subject).to eq('') }
+    end
+
+    context 'integer_number -> text' do
+      let(:last_write_type_champ) { :integer_number }
+      let(:type_champ) { :text }
+      let(:champ_value) { '42' }
+
+      it { expect(subject).to eq('') }
+    end
+
+    context 'integer_number -> decimal_number' do
+      let(:last_write_type_champ) { :integer_number }
+      let(:type_champ) { :decimal_number }
+      let(:champ_value) { '42' }
+
+      it { expect(subject).to eq('42') }
+    end
+
+    context 'decimal_number -> integer_number' do
+      let(:last_write_type_champ) { :decimal_number }
+      let(:type_champ) { :integer_number }
+      let(:champ_value) { '42.1' }
+
+      it { expect(subject).to eq('42.1') }
+    end
+
+    context 'drop_down_list -> multiple_drop_down_list' do
+      let(:last_write_type_champ) { :drop_down_list }
+      let(:type_champ) { :multiple_drop_down_list }
+      let(:champ_value) { type_de_champ.drop_down_options.first }
+
+      it { expect(subject).to eq(champ_value) }
+    end
+
+    context 'multiple_drop_down_list -> drop_down_list' do
+      let(:last_write_type_champ) { :multiple_drop_down_list }
+      let(:type_champ) { :drop_down_list }
+      let(:champ_value) { "[\"#{type_de_champ.drop_down_options.first}\"]" }
+
+      it { expect(subject).to eq('') }
+    end
+  end
 end