diff --git a/app/models/officing/residence.rb b/app/models/officing/residence.rb
index cf69e6aba..8036c8401 100644
--- a/app/models/officing/residence.rb
+++ b/app/models/officing/residence.rb
@@ -68,7 +68,7 @@ class Officing::Residence
   end
 
   def allowed_age?
-    date_of_birth <= User.minimum_required_age.years.ago
+    date_of_birth.age_in_years <= User.minimum_required_age
   end
 
   def geozone
diff --git a/app/models/user.rb b/app/models/user.rb
index 7c72ab4b3..f092a6a7a 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -247,14 +247,7 @@ class User < ActiveRecord::Base
   end
 
   def age
-    if date_of_birth.blank?
-      nil
-    else
-      now = Time.now.utc.to_date
-      now.year - date_of_birth.year - (
-        (now.month > date_of_birth.month || (now.month == date_of_birth.month && now.day >= date_of_birth.day)
-        ) ? 0 : 1)
-    end
+    date_of_birth.try(:age_in_years)
   end
 
   def save_requiring_finish_signup
diff --git a/app/models/verification/management/document.rb b/app/models/verification/management/document.rb
index 4264154d3..f39bf4b90 100644
--- a/app/models/verification/management/document.rb
+++ b/app/models/verification/management/document.rb
@@ -32,7 +32,7 @@ class Verification::Management::Document
   end
 
   def under_age?(response)
-    User.minimum_required_age.years.ago.beginning_of_day < response.date_of_birth.beginning_of_day
+    response.date_of_birth && User.minimum_required_age < response.date_of_birth.age_in_years
   end
 
   def verified?
diff --git a/app/models/verification/residence.rb b/app/models/verification/residence.rb
index eda562671..040460527 100644
--- a/app/models/verification/residence.rb
+++ b/app/models/verification/residence.rb
@@ -36,7 +36,7 @@ class Verification::Residence
 
   def allowed_age
     return if errors[:date_of_birth].any?
-    errors.add(:date_of_birth, I18n.t('verification.residence.new.error_not_allowed_age')) unless self.date_of_birth <= User.minimum_required_age.years.ago
+    errors.add(:date_of_birth, I18n.t('verification.residence.new.error_not_allowed_age')) unless self.date_of_birth.age_in_years <= User.minimum_required_age
   end
 
   def document_number_uniqueness