diff --git a/Gemfile b/Gemfile
index c47f2f81a..b2ba7ba3e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,7 +4,7 @@ git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 ruby File.read('.ruby-version').chomp
 
 gem 'faraday', '~> 2.7'
-gem 'govuk_design_system_formbuilder', '~> 3.3.0'
+gem 'govuk_design_system_formbuilder', '~> 4.0.0'
 gem 'jbuilder', '~> 2.11.5'
 gem 'kaminari'
 gem 'lograge'
diff --git a/Gemfile.lock b/Gemfile.lock
index d03def2c3..f752831db 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -174,21 +174,21 @@ GEM
     faraday-net_http (3.0.2)
     globalid (1.1.0)
       activesupport (>= 5.0)
-    govuk_design_system_formbuilder (3.3.0)
+    govuk_design_system_formbuilder (4.0.0)
       actionview (>= 6.1)
       activemodel (>= 6.1)
       activesupport (>= 6.1)
-      html-attributes-utils (~> 0.9, >= 0.9.2)
+      html-attributes-utils (~> 1)
     gyoku (1.4.0)
       builder (>= 2.1.2)
       rexml (~> 3.0)
     hashdiff (1.0.1)
     hashie (5.0.0)
-    html-attributes-utils (0.9.2)
+    html-attributes-utils (1.0.0)
       activesupport (>= 6.1.4.4)
     httpi (3.0.1)
       rack
-    i18n (1.12.0)
+    i18n (1.13.0)
       concurrent-ruby (~> 1.0)
     ice_nine (0.11.2)
     importmap-rails (1.1.6)
@@ -222,9 +222,9 @@ GEM
       railties (>= 4)
       request_store (~> 1.0)
     logstash-event (1.2.02)
-    loofah (2.20.0)
+    loofah (2.21.3)
       crass (~> 1.0.2)
-      nokogiri (>= 1.5.9)
+      nokogiri (>= 1.12.0)
     mail (2.8.1)
       mini_mime (>= 0.1.1)
       net-imap
@@ -234,7 +234,7 @@ GEM
     matrix (0.4.2)
     method_source (1.0.0)
     mini_mime (1.1.2)
-    mini_portile2 (2.8.1)
+    mini_portile2 (2.8.2)
     minitest (5.18.0)
     moj-simple-jwt-auth (0.1.0)
       json
@@ -250,8 +250,8 @@ GEM
     net-smtp (0.3.3)
       net-protocol
     nio4r (2.5.9)
-    nokogiri (1.14.3)
-      mini_portile2 (~> 2.8.0)
+    nokogiri (1.15.2)
+      mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     nori (2.6.0)
     omniauth (2.1.1)
@@ -443,7 +443,7 @@ DEPENDENCIES
   dotenv-rails
   erb_lint
   faraday (~> 2.7)
-  govuk_design_system_formbuilder (~> 3.3.0)
+  govuk_design_system_formbuilder (~> 4.0.0)
   hmcts_common_platform!
   importmap-rails
   jbuilder (~> 2.11.5)
diff --git a/app/views/steps/case/case_type/edit.html.erb b/app/views/steps/case/case_type/edit.html.erb
index 92f87cd7c..381ef2847 100644
--- a/app/views/steps/case/case_type/edit.html.erb
+++ b/app/views/steps/case/case_type/edit.html.erb
@@ -11,13 +11,15 @@
           <% if choice == CaseType::APPEAL_TO_CROWN_COURT %>
 
             <%= f.govuk_radio_button :case_type, choice.value do %>
-              <%= f.govuk_text_field :appeal_maat_id, width: 'one-third', autocomplete: 'off' %>
+              <%= f.govuk_text_field :appeal_maat_id, autocomplete: 'off', width: 'one-third',
+                                     extra_letter_spacing: true %>
             <% end %>
 
           <% elsif choice == CaseType::APPEAL_TO_CROWN_COURT_WITH_CHANGES %>
 
             <%= f.govuk_radio_button :case_type, choice.value do %>
-              <%= f.govuk_text_field :appeal_with_changes_maat_id, width: 'one-third', autocomplete: 'off' %>
+              <%= f.govuk_text_field :appeal_with_changes_maat_id, autocomplete: 'off', width: 'one-third',
+                                     extra_letter_spacing: true %>
               <%= f.govuk_text_area :appeal_with_changes_details %>
             <% end %>
 
diff --git a/app/views/steps/case/charges/edit.html.erb b/app/views/steps/case/charges/edit.html.erb
index 30b182c8c..474b4fadf 100644
--- a/app/views/steps/case/charges/edit.html.erb
+++ b/app/views/steps/case/charges/edit.html.erb
@@ -30,18 +30,12 @@
                                   legend: {
                                     text: t("helpers.legend.#{f.object_name}.date_from", index:),
                                     size: 's'
-                                  },
-                                  hint: {
-                                    text: t("helpers.hint.#{f.object_name}.date_from")
-                                  }%>
+                                  } %>
 
           <%= od.govuk_date_field :date_to, maxlength_enabled: true,
                                   legend: {
                                     text: t("helpers.legend.#{f.object_name}.date_to", index:),
                                     size: 's'
-                                  },
-                                  hint: {
-                                    text: t("helpers.hint.#{f.object_name}.date_to")
                                   } %>
 
           <%= od.button t('.remove_button', index:), type: :submit, value: '1', name: od.field_name(:_destroy, index: od.id),
diff --git a/app/views/steps/case/codefendants/edit.html.erb b/app/views/steps/case/codefendants/edit.html.erb
index 42b3252c5..f18934336 100644
--- a/app/views/steps/case/codefendants/edit.html.erb
+++ b/app/views/steps/case/codefendants/edit.html.erb
@@ -14,20 +14,10 @@
         <% index = c.index + 1 %>
 
         <%= c.govuk_fieldset legend: { text: t('.codefendant_legend', index:) }, id: "codefendant_#{index}" do %>
-          <%= c.govuk_text_field :first_name, label: { text: t("helpers.label.#{f.object_name}.first_name") },
-                                 autocomplete: 'off', width: 'three-quarters' %>
-
-          <%= c.govuk_text_field :last_name, label: { text: t("helpers.label.#{f.object_name}.last_name") },
-                                 autocomplete: 'off', width: 'three-quarters' %>
-
-          <%= c.govuk_collection_radio_buttons :conflict_of_interest, c.object.choices,
-                                               :value,
-                                               ->(option) { t("helpers.label.#{f.object_name}.conflict_of_interest_options.#{option}") },
-                                               inline: true,
-                                               legend: {
-                                                 text: t("helpers.legend.#{f.object_name}.conflict_of_interest"),
-                                                 class: 'govuk-fieldset__legend',
-                                               } %>
+          <%= c.govuk_text_field :first_name, autocomplete: 'off', width: 'three-quarters' %>
+          <%= c.govuk_text_field :last_name, autocomplete: 'off', width: 'three-quarters' %>
+
+          <%= c.govuk_collection_radio_buttons :conflict_of_interest, c.object.choices, :value, inline: true %>
 
           <%= c.button t('.remove_button', index:), type: :submit, value: '1', name: c.field_name(:_destroy, index: nil),
                        class: %w[govuk-button govuk-button--warning],
diff --git a/app/views/steps/case/urn/edit.html.erb b/app/views/steps/case/urn/edit.html.erb
index ac2b7804b..68cfa1499 100644
--- a/app/views/steps/case/urn/edit.html.erb
+++ b/app/views/steps/case/urn/edit.html.erb
@@ -5,8 +5,10 @@
   <div class="govuk-grid-column-two-thirds">
     <%= govuk_error_summary(@form_object) %>
     <%= step_form @form_object do |f| %>
-      <%= f.govuk_text_field :urn, autocomplete: 'off', width: 'one-third', label: { tag: 'h1', size: 'xl' }  do %>
-        <p><%= t('.urn_guidance') %></p>
+      <%= f.govuk_text_field :urn, autocomplete: 'off', width: 'one-third',
+                             extra_letter_spacing: true,
+                             label: { tag: 'h1', size: 'xl' } do %>
+        <p class="govuk-body"><%= t('.urn_guidance') %></p>
       <% end %>
 
       <%= f.continue_button %>
diff --git a/app/views/steps/client/contact_details/edit.html.erb b/app/views/steps/client/contact_details/edit.html.erb
index 1add48186..e37f87e71 100644
--- a/app/views/steps/client/contact_details/edit.html.erb
+++ b/app/views/steps/client/contact_details/edit.html.erb
@@ -12,7 +12,9 @@
                                            @form_object.choices,
                                            :value %>
 
-      <%= f.govuk_phone_field :telephone_number, autocomplete: 'off', width: 'one-third', label: { size: 'm' } %>
+      <%= f.govuk_phone_field :telephone_number, autocomplete: 'off', width: 'one-third',
+                              extra_letter_spacing: true,
+                              label: { size: 'm' } %>
 
       <%= f.continue_button %>
     <% end %>
diff --git a/app/views/steps/client/has_nino/edit.html.erb b/app/views/steps/client/has_nino/edit.html.erb
index 793eb7f95..2e38a2805 100644
--- a/app/views/steps/client/has_nino/edit.html.erb
+++ b/app/views/steps/client/has_nino/edit.html.erb
@@ -6,7 +6,9 @@
     <%= govuk_error_summary(@form_object) %>
 
     <%= step_form @form_object do |f| %>
-      <%= f.govuk_text_field :nino, autocomplete: 'off', width: 'one-third', label: { tag: 'h1', size: 'xl' } %>
+      <%= f.govuk_text_field :nino, autocomplete: 'off', width: 'one-third',
+                             extra_letter_spacing: true,
+                             label: { tag: 'h1', size: 'xl' } %>
 
       <p class='govuk-body govuk-!-margin-bottom-6'>
         <%= link_to t('.eforms_link'), steps_client_nino_exit_path %>
diff --git a/app/views/steps/submission/declaration/edit.en.html.erb b/app/views/steps/submission/declaration/edit.en.html.erb
index 10a7c55f7..53f8b1f5d 100644
--- a/app/views/steps/submission/declaration/edit.en.html.erb
+++ b/app/views/steps/submission/declaration/edit.en.html.erb
@@ -47,7 +47,8 @@
       <%= f.govuk_fieldset legend: { text: t('.legal_representative_legend') } do %>
         <%= f.govuk_text_field :legal_rep_first_name, autocomplete: 'off', width: 'three-quarters' %>
         <%= f.govuk_text_field :legal_rep_last_name, autocomplete: 'off', width: 'three-quarters' %>
-        <%= f.govuk_text_field :legal_rep_telephone, autocomplete: 'off', width: 'three-quarters' %>
+        <%= f.govuk_text_field :legal_rep_telephone, autocomplete: 'off', width: 'three-quarters',
+                               extra_letter_spacing: true %>
       <% end %>
 
       <%= f.continue_button(primary: :save_and_submit) %>
diff --git a/config/importmap.rb b/config/importmap.rb
index 5f662895a..2e7bfba24 100644
--- a/config/importmap.rb
+++ b/config/importmap.rb
@@ -1,6 +1,6 @@
 # Pin npm packages by running ./bin/importmap
 
 pin "application", preload: true
-pin "govuk-frontend", to: "https://ga.jspm.io/npm:govuk-frontend@4.5.0/govuk-esm/all.mjs"
+pin "govuk-frontend", to: "https://ga.jspm.io/npm:govuk-frontend@4.6.0/govuk-esm/all.mjs"
 pin_all_from "app/javascript/local", under: "local"
 pin "accessible-autocomplete", to: "https://ga.jspm.io/npm:accessible-autocomplete@2.0.4/dist/accessible-autocomplete.min.js"
diff --git a/config/locales/en/helpers.yml b/config/locales/en/helpers.yml
index e9c7bd703..311e69649 100644
--- a/config/locales/en/helpers.yml
+++ b/config/locales/en/helpers.yml
@@ -44,7 +44,8 @@ en:
       steps_case_has_codefendants_form:
         has_codefendants: Does your client have any co-defendants in this case?
       steps_case_codefendants_form:
-        conflict_of_interest: Is there a conflict of interest with this co-defendant?
+        codefendants_attributes:
+          conflict_of_interest: Is there a conflict of interest with this co-defendant?
       steps_case_hearing_details_form:
         hearing_date: Date of next hearing
       steps_case_ioj_form:
@@ -64,8 +65,9 @@ en:
         urn: For example, ‘12 AB 3456789’.
       steps_case_charges_form:
         offence_name: Add one offence at a time, for example, robbery. You can add more later.
-        date_to: Leave blank if the offence happened on a single date
-        date_from: For example, 27 3 2007
+        offence_dates_attributes:
+          date_from: For example, 27 3 2007
+          date_to: Leave blank if the offence happened on a single date
       steps_case_hearing_details_form:
         hearing_court_name: For example, Cardiff Crown Court
         hearing_date: For example, 27 3 2024
@@ -143,9 +145,10 @@ en:
       steps_case_has_codefendants_form:
         has_codefendants_options: *YESNO
       steps_case_codefendants_form:
-        first_name: First name
-        last_name: Last name
-        conflict_of_interest_options: *YESNO
+        codefendants_attributes:
+          first_name: First name
+          last_name: Last name
+          conflict_of_interest_options: *YESNO
       steps_case_hearing_details_form:
         hearing_court_name: Court name
       steps_case_ioj_form:
diff --git a/config/locales/en/steps.yml b/config/locales/en/steps.yml
index 97d6e2c13..39f2f1cd5 100644
--- a/config/locales/en/steps.yml
+++ b/config/locales/en/steps.yml
@@ -30,7 +30,7 @@ en:
         edit:
           page_title: Enter your client’s details
           heading: Enter your client’s details
-          full_name_legend: Client's full name
+          full_name_legend: Client’s full name
       has_nino:
         edit:
           page_title: Enter your client’s NINO
diff --git a/package.json b/package.json
index 2227aac74..1e28dcf24 100644
--- a/package.json
+++ b/package.json
@@ -2,10 +2,10 @@
   "name": "laa-apply-for-criminal-legal-aid",
   "private": "true",
   "dependencies": {
-    "govuk-frontend": "4.5.0",
-    "@ministryofjustice/frontend": "1.6.4"
+    "@ministryofjustice/frontend": "1.6.6",
+    "govuk-frontend": "4.6.0"
   },
   "scripts": {
-    "postinstall": "bin/importmap pin govuk-frontend@4.5.0"
+    "postinstall": "bin/importmap pin govuk-frontend@4.6.0"
   }
 }
diff --git a/spec/views/steps/submission/shared/_date_answer.html.erb_spec.rb b/spec/views/steps/submission/shared/_date_answer.html.erb_spec.rb
index 0d11811ef..4955af7a8 100644
--- a/spec/views/steps/submission/shared/_date_answer.html.erb_spec.rb
+++ b/spec/views/steps/submission/shared/_date_answer.html.erb_spec.rb
@@ -30,7 +30,7 @@
 
     it 'renders the expected row' do
       assert_select 'div.govuk-summary-list__row', 1 do
-        assert_select 'dd.govuk-summary-list__value', text: '22 November 2008 12:00'
+        assert_select 'dd.govuk-summary-list__value', text: '22 November 2008 12:00am'
       end
     end
   end
diff --git a/yarn.lock b/yarn.lock
index 865fbb51c..8766d237e 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2,18 +2,18 @@
 # yarn lockfile v1
 
 
-"@ministryofjustice/frontend@1.6.4":
-  version "1.6.4"
-  resolved "https://registry.yarnpkg.com/@ministryofjustice/frontend/-/frontend-1.6.4.tgz#396ffdc1699253671c8bc93ffa879735b8d4e8da"
-  integrity sha512-+tL1FolgPxo1jYw6zDcvqyVA0zHigW0QAn4NQbfHKwOb/rhny49iVud6PhzK4zguZds+sQQ0yzHpanROsmWLOw==
+"@ministryofjustice/frontend@1.6.6":
+  version "1.6.6"
+  resolved "https://registry.yarnpkg.com/@ministryofjustice/frontend/-/frontend-1.6.6.tgz#120b117a796f3c297b3f05d4dba62568d66554e7"
+  integrity sha512-fbU3NEMmSmR0h8t4cSlhdl5c+Mc+cR94Or19R1ipGxfrnpmQpiN/Yc6h61n2pIMZBR5DIYvlO1GkDopVPS5qQw==
   dependencies:
     govuk-frontend "^3.0.0 || ^4.0.0"
     moment "^2.27.0"
 
-govuk-frontend@4.5.0, "govuk-frontend@^3.0.0 || ^4.0.0":
-  version "4.5.0"
-  resolved "https://registry.yarnpkg.com/govuk-frontend/-/govuk-frontend-4.5.0.tgz#64759e39efbaa81f9cb7a35cc6cff6fd9fa619ef"
-  integrity sha512-gZHDqf5vdlHjmx0NGJiNT12XLyR3d5KCS4AnlC3xTWOObJ0kQROrkIFyp3w4/PY3EQiYdgacVaJ6lizzygnzYw==
+govuk-frontend@4.6.0, "govuk-frontend@^3.0.0 || ^4.0.0":
+  version "4.6.0"
+  resolved "https://registry.yarnpkg.com/govuk-frontend/-/govuk-frontend-4.6.0.tgz#662b41f7c468bb5468441218c720f0b31c948cbd"
+  integrity sha512-pLJVHVvfsTmNDBH/YBCMyuqSMCQmOrNQXoThdcAzhXJVbuaWnGc1URvjOR7EJeZyOm101fHDjzTkTvpEy6zfiw==
 
 moment@^2.27.0:
   version "2.29.4"