diff --git a/Gemfile.lock b/Gemfile.lock
index 342024da..d6cfe519 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -166,7 +166,8 @@ GEM
     console (1.17.0)
       fiber-annotation
       fiber-local
-    crack (0.4.5)
+    crack (1.0.0)
+      bigdecimal
       rexml
     crass (1.0.6)
     date (3.3.4)
@@ -241,7 +242,7 @@ GEM
       activemodel (>= 6.1)
       activesupport (>= 6.1)
       html-attributes-utils (~> 1)
-    hashdiff (1.0.1)
+    hashdiff (1.1.0)
     high_voltage (3.1.2)
     html-attributes-utils (1.0.2)
       activesupport (>= 6.1.4.4)
@@ -280,7 +281,7 @@ GEM
     minitest (5.21.2)
     multi_json (1.15.0)
     mutex_m (0.2.0)
-    net-imap (0.4.9.1)
+    net-imap (0.4.10)
       date
       net-protocol
     net-pop (0.1.2)
@@ -291,10 +292,10 @@ GEM
       net-protocol
     netrc (0.11.0)
     nio4r (2.7.0)
-    nokogiri (1.16.0)
+    nokogiri (1.16.2)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
-    nokogiri (1.16.0-x86_64-linux)
+    nokogiri (1.16.2-x86_64-linux)
       racc (~> 1.4)
     notifications-ruby-client (6.0.0)
       jwt (>= 1.5, < 3)
@@ -481,7 +482,7 @@ GEM
     validates_email_format_of (1.7.2)
       i18n
     vcr (6.2.0)
-    webmock (3.19.1)
+    webmock (3.20.0)
       addressable (>= 2.8.0)
       crack (>= 0.3.2)
       hashdiff (>= 0.4.0, < 2.0.0)
diff --git a/app/models/flood_risk_engine/enrollment.rb b/app/models/flood_risk_engine/enrollment.rb
index 699f9034..c60bff94 100644
--- a/app/models/flood_risk_engine/enrollment.rb
+++ b/app/models/flood_risk_engine/enrollment.rb
@@ -4,9 +4,6 @@ module FloodRiskEngine
   class Enrollment < ApplicationRecord
     has_secure_token
 
-    # We don't define the inverse relationship of applicant_contact as, in WEX at least,
-    # we query never from contact to its enrollment
-    belongs_to :applicant_contact, class_name: "Contact"
     belongs_to :organisation
     delegate :org_type, :partners, to: :organisation, allow_nil: true
 
@@ -22,8 +19,8 @@ class Enrollment < ApplicationRecord
     belongs_to :secondary_contact, class_name: "Contact"
 
     belongs_to :reference_number
-    def reference_number
-      super.try(:number)
+    def ref_number
+      reference_number.number
     end
 
     has_one(
diff --git a/app/models/flood_risk_engine/location.rb b/app/models/flood_risk_engine/location.rb
index 154a8b19..99ffec69 100644
--- a/app/models/flood_risk_engine/location.rb
+++ b/app/models/flood_risk_engine/location.rb
@@ -5,7 +5,7 @@
 module FloodRiskEngine
   class Location < ApplicationRecord
     belongs_to :locatable, polymorphic: true
-    belongs_to :water_management_area
+    belongs_to :water_management_area, optional: true
 
     before_save :process_grid_reference
 
diff --git a/app/services/flood_risk_engine/notify/enrollment_submitted_email_service.rb b/app/services/flood_risk_engine/notify/enrollment_submitted_email_service.rb
index 22989681..de0a0d2c 100644
--- a/app/services/flood_risk_engine/notify/enrollment_submitted_email_service.rb
+++ b/app/services/flood_risk_engine/notify/enrollment_submitted_email_service.rb
@@ -10,7 +10,7 @@ def notify_options
           email_address: @recipient_address,
           template_id:,
           personalisation: {
-            registration_number: @enrollment.reference_number,
+            registration_number: @enrollment.ref_number,
             exemption_description: enrollment_description
           }
         }
diff --git a/app/services/flood_risk_engine/registration_completion_service.rb b/app/services/flood_risk_engine/registration_completion_service.rb
index 10a3b7df..6c578862 100644
--- a/app/services/flood_risk_engine/registration_completion_service.rb
+++ b/app/services/flood_risk_engine/registration_completion_service.rb
@@ -8,8 +8,6 @@ def run(transient_registration:)
       @registration = nil
 
       @transient_registration.with_lock do
-        @transient_registration.update(workflow_state: :creating_registration)
-
         @registration = Enrollment.new
         transfer_data
         @registration.save!
@@ -22,8 +20,8 @@ def run(transient_registration:)
 
       @registration
     rescue StandardError => e
-      Airbrake.notify(e, reference: @registration&.reference_number) if defined?(Airbrake)
-      Rails.logger.error "Completing registration error: #{e}"
+      Airbrake.notify(e, reference: @registration&.ref_number) if defined?(Airbrake)
+      Rails.logger.error "Completing registration error: #{e}\n#{@registration.errors.inspect}"
 
       raise e
     end
@@ -70,7 +68,7 @@ def add_secondary_contact
     end
 
     def add_partnership_organisation
-      @registration.organisation = Organisation.new(
+      @registration.organisation = Organisation.create!(
         org_type:
       )
 
@@ -137,6 +135,9 @@ def update_status_and_assistance_mode
     end
 
     def update_water_management_area
+      # location.id must be present for ActiveJob serialization:
+      @registration.exemption_location.save!
+
       UpdateWaterManagementAreaJob.perform_later(@registration.exemption_location)
     end
 
diff --git a/app/views/flood_risk_engine/enrollment_mailer/submitted.html.erb b/app/views/flood_risk_engine/enrollment_mailer/submitted.html.erb
index 7adb482a..1a1d44fd 100644
--- a/app/views/flood_risk_engine/enrollment_mailer/submitted.html.erb
+++ b/app/views/flood_risk_engine/enrollment_mailer/submitted.html.erb
@@ -5,7 +5,7 @@
 <% end %>
 
 <h2>
-  <%= t('.reference_number_heading', reference_number: @enrollment.reference_number) %>
+  <%= t('.ref_number_heading', reference_number: @enrollment.ref_number) %>
 </h2>
 
 <h2 class="border-top"><%= t('.exemption_heading') %></h2>
diff --git a/app/views/flood_risk_engine/enrollment_mailer/submitted.text.erb b/app/views/flood_risk_engine/enrollment_mailer/submitted.text.erb
index 50acd607..56ee5101 100644
--- a/app/views/flood_risk_engine/enrollment_mailer/submitted.text.erb
+++ b/app/views/flood_risk_engine/enrollment_mailer/submitted.text.erb
@@ -1,7 +1,7 @@
 <%= t('.registration_submitted') %> <%= t('.please_wait') %>
 --------------------------------------------------------
 <%= "\r\n" %>
-<%= t('.text_reference_number', reference_number: @enrollment.reference_number) %>
+<%= t('.text_reference_number', reference_number: @enrollment.ref_number) %>
 <%= "\r\n" %>
 <%= t(".exemption_heading") %>
 <%= @exemption.summary %> <%= @exemption.code %>.
diff --git a/app/views/flood_risk_engine/registration_complete_forms/new.html.erb b/app/views/flood_risk_engine/registration_complete_forms/new.html.erb
index 9d6e9fa3..ed8652d0 100644
--- a/app/views/flood_risk_engine/registration_complete_forms/new.html.erb
+++ b/app/views/flood_risk_engine/registration_complete_forms/new.html.erb
@@ -13,7 +13,7 @@
           <div class="govuk-panel__body">
             <%= t(".reference") %><br />
             <strong>
-              <span id="reg_identifier"><%= @enrollment.reference_number %></span>
+              <span id="reg_identifier"><%= @enrollment.ref_number %></span>
             </strong>
           </div>
         </div>
diff --git a/config/locales/flood_risk_engine/company_address_manual_forms.en.yml b/config/locales/flood_risk_engine/company_address_manual_forms.en.yml
index a626c72a..450b8052 100644
--- a/config/locales/flood_risk_engine/company_address_manual_forms.en.yml
+++ b/config/locales/flood_risk_engine/company_address_manual_forms.en.yml
@@ -10,8 +10,8 @@ en:
           soleTrader: What’s the address of the business?
           charity: What’s the address of the charity or trust?
         title: *heading
-        os_places_error_heading: Our address finder is not working
-        os_places_error_text: Please enter the address below.
+        address_finder_error_heading: Our address finder is not working
+        address_finder_error_text: Please enter the address below.
         preset_postcode_label: Postcode
         postcode_change_link: Change postcode
         error_heading: Something is wrong
diff --git a/spec/models/flood_risk_engine/enrollment_spec.rb b/spec/models/flood_risk_engine/enrollment_spec.rb
index 8898dac6..34b0c03a 100644
--- a/spec/models/flood_risk_engine/enrollment_spec.rb
+++ b/spec/models/flood_risk_engine/enrollment_spec.rb
@@ -6,7 +6,6 @@ module FloodRiskEngine
   RSpec.describe Enrollment do
     let(:enrollment) { create(:enrollment) }
 
-    it { is_expected.to belong_to(:applicant_contact) }
     it { is_expected.to belong_to(:organisation) }
     it { is_expected.to have_one(:exemption_location).dependent(:restrict_with_exception) }
 
@@ -16,7 +15,7 @@ module FloodRiskEngine
       end
 
       it "is of the right format" do
-        expect(enrollment.reference_number).to match(/EXFRA\d{6}/)
+        expect(enrollment.ref_number).to match(/EXFRA\d{6}/)
       end
     end
 
diff --git a/spec/services/flood_risk_engine/notify/enrollment_submitted_email_service_spec.rb b/spec/services/flood_risk_engine/notify/enrollment_submitted_email_service_spec.rb
index 812ade2a..32570a9b 100644
--- a/spec/services/flood_risk_engine/notify/enrollment_submitted_email_service_spec.rb
+++ b/spec/services/flood_risk_engine/notify/enrollment_submitted_email_service_spec.rb
@@ -23,7 +23,7 @@ module Notify
             email_address: recipient_address,
             template_id:,
             personalisation: {
-              registration_number: enrollment.reference_number,
+              registration_number: enrollment.ref_number,
               exemption_description:
             }
           }
diff --git a/spec/services/flood_risk_engine/registration_completion_service_spec.rb b/spec/services/flood_risk_engine/registration_completion_service_spec.rb
index ebe6bed3..35967401 100644
--- a/spec/services/flood_risk_engine/registration_completion_service_spec.rb
+++ b/spec/services/flood_risk_engine/registration_completion_service_spec.rb
@@ -31,7 +31,7 @@ module FloodRiskEngine
         expect(enrollment.submitted_at).to eq(stub_time)
       end
 
-      it "assigns the correct correspondance contact to the new enrollment" do
+      it "assigns the correct correspondence contact to the new enrollment" do
         correspondence_contact_attributes = {
           "full_name" => new_registration.contact_name,
           "email_address" => new_registration.contact_email,
@@ -117,7 +117,7 @@ module FloodRiskEngine
       it "assigns the correct reference number" do
         run_service
 
-        expect(enrollment.reference_number).to eq(ReferenceNumber.last.number)
+        expect(enrollment.ref_number).to eq(ReferenceNumber.last.number)
       end
 
       it "assigns the status" do