diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index e798b14..c9be8b5 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,11 +1,27 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2024-08-20 08:53:30 UTC using RuboCop version 1.64.1.
+# on 2024-08-24 12:41:44 UTC using RuboCop version 1.65.1.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
+# Offense count: 2
+# Configuration parameters: AllowedMethods, AllowedPatterns.
+Metrics/CyclomaticComplexity:
+  Max: 11
+
+# Offense count: 1
+# Configuration parameters: CountComments, Max, CountAsOne, AllowedMethods, AllowedPatterns.
+Metrics/MethodLength:
+  Exclude:
+    - 'app/controllers/members_controller.rb'
+
+# Offense count: 2
+# Configuration parameters: AllowedMethods, AllowedPatterns.
+Metrics/PerceivedComplexity:
+  Max: 11
+
 # Offense count: 2
 # Configuration parameters: Include.
 # Include: app/controllers/**/*.rb, app/mailers/**/*.rb
diff --git a/app/models/member.rb b/app/models/member.rb
index 75690f1..03eb70e 100644
--- a/app/models/member.rb
+++ b/app/models/member.rb
@@ -21,11 +21,14 @@ class Member < ApplicationRecord
             :address,
             :postal_code,
             :email,
+            :tax_code,
             :municipality, presence: true
 
   validates :email, format: { with: URI::MailTo::EMAIL_REGEXP }
   validates :groups, length: { minimum: 1 }
 
+  validate :at_least_a_parent?, if: -> { born_at && born_at >= (Time.zone.today - 18.years) }
+
   scope :with_expiring_medical_certificate,
         -> { where(medical_certificate_expires_at: Time.zone.today.beginning_of_day..2.months.from_now) }
 
@@ -76,4 +79,46 @@ def payments_status
 
     'ok'
   end
+
+  private
+
+  def at_least_a_parent?
+    return true if first_parent_present? || second_parent_present?
+
+    errors.add(:at_least_a_parent, 'add at least a parent')
+  end
+
+  def first_parent_present?
+    if first_parent_first_name.present? &&
+       first_parent_last_name.present? &&
+       first_parent_born_at.present? &&
+       first_parent_born_in.present? &&
+       first_parent_citizenship.present? &&
+       first_parent_address.present? &&
+       first_parent_postal_code.present? &&
+       first_parent_email.present? &&
+       first_parent_tax_code.present? &&
+       first_parent_municipality.present?
+      return true
+    end
+
+    false
+  end
+
+  def second_parent_present?
+    if second_parent_first_name.present? &&
+       second_parent_last_name.present? &&
+       second_parent_born_at.present? &&
+       second_parent_born_in.present? &&
+       second_parent_citizenship.present? &&
+       second_parent_address.present? &&
+       second_parent_postal_code.present? &&
+       second_parent_email.present? &&
+       second_parent_tax_code.present? &&
+       second_parent_municipality.present?
+      return true
+    end
+
+    false
+  end
 end
diff --git a/test/fixtures/clubs.yml b/test/fixtures/clubs.yml
new file mode 100644
index 0000000..f492b17
--- /dev/null
+++ b/test/fixtures/clubs.yml
@@ -0,0 +1,5 @@
+# Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+club:
+  name: the club
+  email: club@email.com
diff --git a/test/fixtures/groups.yml b/test/fixtures/groups.yml
new file mode 100644
index 0000000..2c3fbdc
--- /dev/null
+++ b/test/fixtures/groups.yml
@@ -0,0 +1,4 @@
+# Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+group:
+  name: the group
diff --git a/test/fixtures/members.yml b/test/fixtures/members.yml
index e251a8d..4462183 100644
--- a/test/fixtures/members.yml
+++ b/test/fixtures/members.yml
@@ -1,13 +1,83 @@
 # Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
 
-gino:
+adult:
+  club: club
+  groups: [group]
   first_name: gino
   last_name: ginetti
   email: gino.ginetti@email.com
-  born_at: 2000-01-02
+  born_at: <%= Time.zone.today - 20.years %>
   born_in: comunino
   citizenship: italiano
   address: via delle vie 123 R
   postal_code: 12345
+  tax_code: TAXCODE
   province: provinciona
-  municipality: comunone
\ No newline at end of file
+  municipality: comunone
+
+minor_with_no_parents:
+  club: club
+  groups: [group]
+  first_name: gino
+  last_name: ginetti
+  email: gino.ginetti@email.com
+  born_at: <%= Time.zone.today - 17.years %>
+  born_in: comunino
+  citizenship: italiano
+  address: via delle vie 123 R
+  postal_code: 12345
+  tax_code: TAXCODE
+  province: provinciona
+  municipality: comunone
+
+minor_with_first_parent:
+  club: club
+  groups: [group]
+  first_name: gino
+  last_name: ginetti
+  email: gino.ginetti@email.com
+  born_at: <%= Time.zone.today - 17.years %>
+  born_in: comunino
+  citizenship: italiano
+  address: via delle vie 123 R
+  postal_code: 12345
+  tax_code: TAXCODE
+  province: provinciona
+  municipality: comunone
+  first_parent_first_name: gino
+  first_parent_last_name: ginetti
+  first_parent_email: gino.ginetti@email.com
+  first_parent_born_at: <%= Time.zone.today - 30.years %>
+  first_parent_born_in: comunino
+  first_parent_tax_code: TAX_CODE
+  first_parent_citizenship: italiano
+  first_parent_address: via delle vie 123 R
+  first_parent_postal_code: 12345
+  first_parent_province: provinciona
+  first_parent_municipality: comunone
+
+minor_with_second_parent:
+  club: club
+  groups: [group]
+  first_name: gino
+  last_name: ginetti
+  email: gino.ginetti@email.com
+  born_at: <%= Time.zone.today - 17.years %>
+  born_in: comunino
+  citizenship: italiano
+  address: via delle vie 123 R
+  postal_code: 12345
+  province: provinciona
+  tax_code: TAXCODE
+  municipality: comunone
+  second_parent_first_name: gino
+  second_parent_last_name: ginetti
+  second_parent_email: gino.ginetti@email.com
+  second_parent_born_at: <%= Time.zone.today - 30.years %>
+  second_parent_born_in: comunino
+  second_parent_tax_code: TAX_CODE
+  second_parent_citizenship: italiano
+  second_parent_address: via delle vie 123 R
+  second_parent_postal_code: 12345
+  second_parent_province: provinciona
+  second_parent_municipality: comunone
\ No newline at end of file
diff --git a/test/mailers/medical_certificate_mailer_test.rb b/test/mailers/medical_certificate_mailer_test.rb
index 40dda1e..648ddab 100644
--- a/test/mailers/medical_certificate_mailer_test.rb
+++ b/test/mailers/medical_certificate_mailer_test.rb
@@ -4,7 +4,7 @@
 
 class MedicalCertificateMailerTest < ActionMailer::TestCase
   test 'expiring_email' do
-    member = members(:gino)
+    member = members(:adult)
     email = MedicalCertificateMailer.with(member:).expiring_email
 
     assert_emails 1 do
diff --git a/test/models/member_test.rb b/test/models/member_test.rb
index 913d52f..141c455 100644
--- a/test/models/member_test.rb
+++ b/test/models/member_test.rb
@@ -15,4 +15,11 @@ class MemberTest < ActiveSupport::TestCase
     assert(member.errors.key?('address'))
     assert(member.errors.key?('postal_code'))
   end
+
+  test 'has at least a parent if minor' do
+    assert_not(members(:minor_with_no_parents).valid?)
+
+    assert(members(:minor_with_first_parent).valid?)
+    assert(members(:minor_with_second_parent).valid?)
+  end
 end