diff --git a/app/controllers/api/submissions_controller.rb b/app/controllers/api/submissions_controller.rb
index d70ade71..9d9cfef8 100644
--- a/app/controllers/api/submissions_controller.rb
+++ b/app/controllers/api/submissions_controller.rb
@@ -107,7 +107,8 @@ module Api
     def submissions_params
       params.permit(submission: [{
                       submitters: [[:uuid, :name, :email, :role, :completed, :phone,
-                                    { values: {}, readonly_fields: [] }]]
+                                    { values: {}, readonly_fields: [],
+                                      fields: [%i[name default_value readonly validation_pattern invalid_message]] }]]
                     }])
     end
 
@@ -116,11 +117,15 @@ module Api
 
       Array.wrap(submissions_params).each do |submission|
         submission[:submitters].each_with_index do |submitter, index|
-          next if submitter[:values].blank?
+          default_values = submitter[:values] || {}
+
+          submitter[:fields]&.each { |f| default_values[f[:name]] = f[:default_value] if f[:default_value].present? }
+
+          next if default_values.blank?
 
           values, new_attachments =
             Submitters::NormalizeValues.call(template,
-                                             submitter[:values],
+                                             default_values,
                                              submitter[:role] || template.submitters[index]['name'])
 
           attachments.push(*new_attachments)
diff --git a/app/javascript/submission_form/form.vue b/app/javascript/submission_form/form.vue
index eea283fe..f231e3d4 100644
--- a/app/javascript/submission_form/form.vue
+++ b/app/javascript/submission_form/form.vue
@@ -75,6 +75,9 @@
                 v-model="values[currentField.uuid]"
                 class="base-input !text-2xl w-full"
                 :required="currentField.required"
+                :pattern="currentField.validation?.pattern"
+                :oninvalid="currentField.validation?.message ? `this.setCustomValidity(${JSON.stringify(currentField.validation.message)})` : ''"
+                :oninput="currentField.validation?.message ? `this.setCustomValidity('')` : ''"
                 :placeholder="`${t('type_here')}...${currentField.required ? '' : ` (${t('optional')})`}`"
                 type="text"
                 :name="`values[${currentField.uuid}]`"
diff --git a/lib/submissions/create_from_submitters.rb b/lib/submissions/create_from_submitters.rb
index c571d6a3..771d5e42 100644
--- a/lib/submissions/create_from_submitters.rb
+++ b/lib/submissions/create_from_submitters.rb
@@ -29,17 +29,11 @@ module Submissions
       template_fields = submission.template.fields.deep_dup
 
       submitters_attrs.each_with_index do |submitter_attrs, index|
-        next if submitter_attrs[:readonly_fields].blank?
+        submitter_uuid = find_submitter_uuid(submission.template, submitter_attrs, index)
 
-        uuid = find_submitter_uuid(submission.template, submitter_attrs, index)
+        process_readonly_fields_param(submitter_attrs[:readonly_fields], template_fields, submitter_uuid)
 
-        template_fields.each do |f|
-          next if f['submitter_uuid'] != uuid ||
-                  (!f['name'].in?(submitter_attrs[:readonly_fields]) &&
-                   !f['name'].parameterize.underscore.in?(submitter_attrs[:readonly_fields]))
-
-          f['readonly'] = true
-        end
+        process_fields_param(submitter_attrs[:fields], template_fields, submitter_uuid)
       end
 
       if template_fields != submission.template.fields
@@ -50,6 +44,39 @@ module Submissions
       submission
     end
 
+    def process_readonly_fields_param(readonly_fields, template_fields, submitter_uuid)
+      return if readonly_fields.blank?
+
+      template_fields.each do |f|
+        next if f['submitter_uuid'] != submitter_uuid ||
+                (!f['name'].in?(readonly_fields) &&
+                 !f['name'].parameterize.underscore.in?(readonly_fields))
+
+        f['readonly'] = true
+      end
+    end
+
+    def process_fields_param(fields, template_fields, submitter_uuid)
+      return if fields.blank?
+
+      template_fields.each do |f|
+        next if f['submitter_uuid'] != submitter_uuid
+
+        field_configs = fields.find { |e| e['name'] == f['name'] || e['name'] == f['name'].parameterize.underscore }
+
+        next if field_configs.blank?
+
+        f['readonly'] = field_configs['readonly'] if field_configs['readonly'].present?
+
+        next if field_configs['validation_pattern'].blank?
+
+        f['validation'] = {
+          'pattern' => field_configs['validation_pattern'],
+          'message' => field_configs['invalid_message']
+        }.compact_blank
+      end
+    end
+
     def find_submitter_uuid(template, attrs, index)
       attrs[:uuid].presence ||
         template.submitters.find { |e| e['name'] == attrs[:role] }&.dig('uuid') ||