franchisee.rb

class Franchisee < ActiveRecord::Base
  
  belongs_to :user 
  has_many :phone_numbers, as: :phoneable, dependent: :destroy
  
  accepts_nested_attributes_for :phone_numbers, allow_destroy: true
  
  validates :region_code, presence: true
  
end

phone_number.rb

class PhoneNumber < ActiveRecord::Base
  
  belongs_to :phoneable, :polymorphic => true
  
  validates :phone_number, presence: true
  
end

user.rb

class User < ActiveRecord::Base
  
  has_one :franchisee, dependent: :destroy

  accepts_nested_attributes_for :franchisee
  
  validates :first_name, presence: true
  validates :last_name, presence: true

end