diff --git a/app/controllers/case_logs_controller.rb b/app/controllers/case_logs_controller.rb
index 56919deda..de7501375 100644
--- a/app/controllers/case_logs_controller.rb
+++ b/app/controllers/case_logs_controller.rb
@@ -27,9 +27,11 @@ class CaseLogsController < ApplicationController
     previous_page = params[:previous_page]
     questions_for_page = form.questions_for_page(previous_page).keys
     answers_for_page = page_params(questions_for_page).select { |k, _v| questions_for_page.include?(k) }
-    @case_log.update!(answers_for_page)
-    next_page = form.next_page(previous_page)
-    redirect_to(send("case_log_#{next_page}_path", @case_log))
+    if @case_log.valid?
+      @case_log.update!(answers_for_page)
+      next_page = form.next_page(previous_page)
+      redirect_to(send("case_log_#{next_page}_path", @case_log))
+    end
   end
 
   form = Form.new(2021, 2022)
diff --git a/app/models/case_log.rb b/app/models/case_log.rb
index 3f860cc08..01092a240 100644
--- a/app/models/case_log.rb
+++ b/app/models/case_log.rb
@@ -1,3 +1,19 @@
+class CaseLogValidator < ActiveModel::Validator
+  def validate_tenant_age(record)
+    if record.tenant_age < 0
+      record.errors.add :base, "Age needs to be above 0"
+    elsif record.tenant_age > 120
+      record.errors.add :base, "Age needs to be below 120"
+    end
+    binding.pry
+  end
+
+  def validate(record)
+    validate_tenant_age(record)
+  end
+end
+
 class CaseLog < ApplicationRecord
   enum status: { "in progress" => 0, "submitted" => 1 }
+  validates_with CaseLogValidator
 end
diff --git a/db/schema.rb b/db/schema.rb
index e3215a238..4dab74fee 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -27,7 +27,6 @@ ActiveRecord::Schema.define(version: 2021_09_24_143031) do
     t.string "previous_housing_situation"
     t.integer "prior_homelessness"
     t.string "armed_forces"
-    t.string "postcode"
     t.string "tenant_economic_status"
     t.integer "household_number_of_other_members"
     t.string "person_2_relationship"
@@ -58,6 +57,7 @@ ActiveRecord::Schema.define(version: 2021_09_24_143031) do
     t.integer "person_8_age"
     t.string "person_8_gender"
     t.string "person_8_economic"
+    t.string "postcode"
     t.string "homelessness"
     t.string "last_settled_home"
     t.string "benefit_cap_spare_room_subsidy"