diff --git a/psd-web/app/controllers/investigations/ownership_controller.rb b/psd-web/app/controllers/investigations/ownership_controller.rb
index dc638ff805..516bbebad2 100644
--- a/psd-web/app/controllers/investigations/ownership_controller.rb
+++ b/psd-web/app/controllers/investigations/ownership_controller.rb
@@ -2,42 +2,37 @@ class Investigations::OwnershipController < ApplicationController
   include Wicked::Wizard
   before_action :set_investigation
   before_action :authorize_user
-  before_action :potential_owner, only: %i[show create]
-  before_action :store_owner, only: %i[update]
 
   steps :"select-owner", :confirm
 
   def show
-    @potential_owner = potential_owner&.decorate
+    @potential_owner = form.owner&.decorate
     render_wizard
   end
 
   def new
-    clear_session
+    session[session_store_key] = nil
     redirect_to wizard_path(steps.first, request.query_parameters)
   end
 
   def update
-    if owner_valid?
-      redirect_to next_wizard_path
-    else
-      render_wizard
-    end
+    return render_wizard unless form.valid?
+
+    session[session_store_key] = form.attributes.compact
+    redirect_to next_wizard_path
   end
 
   def create
-    @investigation.owner = potential_owner
-    @investigation.owner_rationale = params[:investigation][:owner_rationale]
-    @investigation.save
-    redirect_to investigation_path(@investigation), flash: { success: "#{@investigation.case_type.upcase_first} owner changed to #{potential_owner.decorate.display_name}" }
-  end
+    ChangeCaseOwner.call!(investigation: @investigation, owner: form.owner, rationale: form.owner_rationale, user: current_user)
 
-private
+    session[session_store_key] = nil
 
-  def clear_session
-    session[:owner_id] = nil
+    message = "#{@investigation.case_type.upcase_first} owner changed to #{form.owner.decorate.display_name(viewer: current_user)}"
+    redirect_to investigation_path(@investigation), flash: { success: message }
   end
 
+private
+
   def set_investigation
     @investigation = Investigation.find_by!(pretty_id: params[:investigation_pretty_id]).decorate
   end
@@ -46,7 +41,12 @@ def authorize_user
     authorize @investigation, :change_owner_or_status?
   end
 
-  def owner_params
+  def session_store_key
+    "update_case_owner_#{@investigation.pretty_id}_params"
+  end
+
+  def form_params
+    params[:investigation] ||= {}
     params[:investigation][:owner_id] = case params[:investigation][:owner_id]
                                         when "someone_in_your_team"
                                           params[:investigation][:select_team_member]
@@ -59,23 +59,14 @@ def owner_params
                                         else
                                           params[:investigation][:owner_id]
                                         end
-    params.require(:investigation).permit(:owner_id)
-  end
-
-  def store_owner
-    session[:owner_id] = owner_params[:owner_id]
+    params.require(:investigation).permit(:owner_id, :owner_rationale).merge(session_params)
   end
 
-  def owner_valid?
-    if step == :"select-owner"
-      if potential_owner.nil?
-        @investigation.errors.add(:owner_id, :invalid, message: "Select case owner")
-      end
-    end
-    @investigation.errors.empty?
+  def session_params
+    session[session_store_key] || {}
   end
 
-  def potential_owner
-    User.find_by(id: session[:owner_id]) || Team.find_by(id: session[:owner_id])
+  def form
+    @form ||= ChangeCaseOwnerForm.new(form_params)
   end
 end
diff --git a/psd-web/app/forms/change_case_owner_form.rb b/psd-web/app/forms/change_case_owner_form.rb
new file mode 100644
index 0000000000..e39a2f297f
--- /dev/null
+++ b/psd-web/app/forms/change_case_owner_form.rb
@@ -0,0 +1,28 @@
+class ChangeCaseOwnerForm
+  include ActiveModel::Model
+  include ActiveModel::Attributes
+
+  attribute :owner_id
+  attribute :owner_rationale
+
+  validates_presence_of :owner_id
+  validate :new_owner_must_be_active_user_or_team
+
+  def owner
+    user || team
+  end
+
+private
+
+  def new_owner_must_be_active_user_or_team
+    errors.add(:owner_id, :not_found) unless owner
+  end
+
+  def user
+    @user ||= User.active.find_by(id: owner_id)
+  end
+
+  def team
+    @team ||= Team.find_by(id: owner_id)
+  end
+end
diff --git a/psd-web/app/models/activity.rb b/psd-web/app/models/activity.rb
index 16aaa5f493..377db73b33 100644
--- a/psd-web/app/models/activity.rb
+++ b/psd-web/app/models/activity.rb
@@ -17,8 +17,13 @@ def attachments
     {}
   end
 
-  def subtitle
-    "#{subtitle_slug} by #{source&.show}, #{pretty_date_stamp}"
+  # Can be overridden by child classes but sometimes need to pass in user
+  def title(_user)
+    super()
+  end
+
+  def subtitle(user)
+    "#{subtitle_slug} by #{source&.show(user)}, #{pretty_date_stamp}"
   end
 
   def search_index;  end
@@ -31,7 +36,7 @@ def can_display_all_data?(_user)
     true
   end
 
-  def restricted_title
+  def restricted_title(_user)
     # where necessary should be implemented by subclasses
   end
 
diff --git a/psd-web/app/models/audit_activity/correspondence/add_email.rb b/psd-web/app/models/audit_activity/correspondence/add_email.rb
index 7955ab660f..a9ac92087e 100644
--- a/psd-web/app/models/audit_activity/correspondence/add_email.rb
+++ b/psd-web/app/models/audit_activity/correspondence/add_email.rb
@@ -48,7 +48,7 @@ def self.build_email_address(correspondence)
     output + "<br>"
   end
 
-  def restricted_title
+  def restricted_title(_user)
     "Email added"
   end
 
diff --git a/psd-web/app/models/audit_activity/correspondence/add_meeting.rb b/psd-web/app/models/audit_activity/correspondence/add_meeting.rb
index 585be78a56..4cc9b660c2 100644
--- a/psd-web/app/models/audit_activity/correspondence/add_meeting.rb
+++ b/psd-web/app/models/audit_activity/correspondence/add_meeting.rb
@@ -23,7 +23,7 @@ def activity_type
     "meeting"
   end
 
-  def restricted_title
+  def restricted_title(_user)
     "Meeting added"
   end
 
diff --git a/psd-web/app/models/audit_activity/correspondence/add_phone_call.rb b/psd-web/app/models/audit_activity/correspondence/add_phone_call.rb
index 88adf4a726..a0d6a828c2 100644
--- a/psd-web/app/models/audit_activity/correspondence/add_phone_call.rb
+++ b/psd-web/app/models/audit_activity/correspondence/add_phone_call.rb
@@ -39,7 +39,7 @@ def self.build_file_body(correspondence)
     file.attached? ? "Attached: #{sanitize_text file.filename}<br>" : ""
   end
 
-  def restricted_title
+  def restricted_title(_user)
     "Phone call added"
   end
 
diff --git a/psd-web/app/models/audit_activity/document/add.rb b/psd-web/app/models/audit_activity/document/add.rb
index fb10d31cfd..27da39f938 100644
--- a/psd-web/app/models/audit_activity/document/add.rb
+++ b/psd-web/app/models/audit_activity/document/add.rb
@@ -8,7 +8,7 @@ def email_update_text(viewer = nil)
     "Document was attached to the #{investigation.case_type.upcase_first} by #{source&.show(viewer)}."
   end
 
-  def restricted_title
+  def restricted_title(_user)
     "Document added"
   end
 
diff --git a/psd-web/app/models/audit_activity/document/base.rb b/psd-web/app/models/audit_activity/document/base.rb
index 2a4bb3168e..ac713fb088 100644
--- a/psd-web/app/models/audit_activity/document/base.rb
+++ b/psd-web/app/models/audit_activity/document/base.rb
@@ -21,7 +21,7 @@ def attached_image?
     attachment.image?
   end
 
-  def restricted_title; end
+  def restricted_title(_user); end
 
   def can_display_all_data?(user)
     can_be_displayed?(attachment, investigation, user)
diff --git a/psd-web/app/models/audit_activity/document/destroy.rb b/psd-web/app/models/audit_activity/document/destroy.rb
index 16b19991d5..9d6fd6cfb2 100644
--- a/psd-web/app/models/audit_activity/document/destroy.rb
+++ b/psd-web/app/models/audit_activity/document/destroy.rb
@@ -4,7 +4,7 @@ def self.from(document, investigation)
     super(document, investigation, title)
   end
 
-  def restricted_title
+  def restricted_title(_user)
     "Document deleted"
   end
 
diff --git a/psd-web/app/models/audit_activity/document/update.rb b/psd-web/app/models/audit_activity/document/update.rb
index dc3dd004cb..25b1ef6192 100644
--- a/psd-web/app/models/audit_activity/document/update.rb
+++ b/psd-web/app/models/audit_activity/document/update.rb
@@ -22,7 +22,7 @@ def self.description_changed?(document, previous_data)
     document.metadata[:description] != previous_data[:description]
   end
 
-  def restricted_title
+  def restricted_title(_user)
     "Document updated"
   end
 
diff --git a/psd-web/app/models/audit_activity/investigation/add.rb b/psd-web/app/models/audit_activity/investigation/add.rb
index ab016d82dd..f3074f05dd 100644
--- a/psd-web/app/models/audit_activity/investigation/add.rb
+++ b/psd-web/app/models/audit_activity/investigation/add.rb
@@ -31,7 +31,7 @@ def complainant
 
   # title may change after investigation was created, so we retrieve from the
   # metadata stored at the time of creation
-  def title
+  def title(_user)
     return self[:title] if self[:title] # older activities stored this in the database
 
     "#{investigation.case_type.titleize} logged: #{metadata['investigation']['title']}"
@@ -49,8 +49,8 @@ def can_display_all_data?(user)
   end
 
   # Only used for old records prior to metadata implementation
-  def restricted_title
-    title
+  def restricted_title(user)
+    title(user)
   end
 
 private
diff --git a/psd-web/app/models/audit_activity/investigation/automatically_update_owner.rb b/psd-web/app/models/audit_activity/investigation/automatically_update_owner.rb
index 073245e6f8..15b0b50eaa 100644
--- a/psd-web/app/models/audit_activity/investigation/automatically_update_owner.rb
+++ b/psd-web/app/models/audit_activity/investigation/automatically_update_owner.rb
@@ -1,31 +1,31 @@
 class AuditActivity::Investigation::AutomaticallyUpdateOwner < AuditActivity::Investigation::Base
-  def self.from(investigation)
-    title = investigation.owner.id.to_s
-    super(investigation, title)
+  def self.from(*)
+    raise "Deprecated - use DeleteUser.call instead"
   end
 
-  def owner_id
-    # We store owner_id in title field, this is getting it back
-    # Using alias for accessing parent method causes errors elsewhere :(
-    AuditActivity::Investigation::Base.instance_method(:title).bind(self).call
+  def self.build_metadata(owner)
+    {
+      owner_id: owner.id
+    }
   end
 
-  # We store owner_id in title field, this is computing title based on that
-  def title
+  def title(user)
     type = investigation.case_type.capitalize
-    new_owner = (User.find_by(id: owner_id) || Team.find_by(id: owner_id))&.decorate&.display_name
+    new_owner = owner.decorate.display_name(viewer: user)
     "Case owner automatically changed on #{type} to #{new_owner}"
   end
 
-  def subtitle
+  def subtitle(_user)
     "Case owner automatically changed, #{pretty_date_stamp}"
   end
 
-  def entities_to_notify
-    []
-  end
+private
 
-  def email_subject_text; end
+  def owner
+    User.find_by(id: metadata["owner_id"]) || Team.find_by(id: metadata["owner_id"])
+  end
 
-  def email_update_text(viewer = nil); end
+  # Do not send investigation_updated mail when case added. This overrides
+  # inherited functionality in the Activity model :(
+  def notify_relevant_users; end
 end
diff --git a/psd-web/app/models/audit_activity/investigation/team_added.rb b/psd-web/app/models/audit_activity/investigation/team_added.rb
index 2641221a82..d22e4604dc 100644
--- a/psd-web/app/models/audit_activity/investigation/team_added.rb
+++ b/psd-web/app/models/audit_activity/investigation/team_added.rb
@@ -1,6 +1,6 @@
 class AuditActivity::Investigation::TeamAdded < AuditActivity::Investigation::Base
-  def subtitle
-    "Team added by #{source&.show}, #{pretty_date_stamp}"
+  def subtitle(user)
+    "Team added by #{source&.show(user)}, #{pretty_date_stamp}"
   end
 
 private
diff --git a/psd-web/app/models/audit_activity/investigation/team_deleted.rb b/psd-web/app/models/audit_activity/investigation/team_deleted.rb
index 715d5497d8..2f0b42c2b1 100644
--- a/psd-web/app/models/audit_activity/investigation/team_deleted.rb
+++ b/psd-web/app/models/audit_activity/investigation/team_deleted.rb
@@ -1,6 +1,6 @@
 class AuditActivity::Investigation::TeamDeleted < AuditActivity::Investigation::Base
-  def subtitle
-    "Team removed by #{source&.show}, #{pretty_date_stamp}"
+  def subtitle(user)
+    "Team removed by #{source&.show(user)}, #{pretty_date_stamp}"
   end
 
 private
diff --git a/psd-web/app/models/audit_activity/investigation/update_owner.rb b/psd-web/app/models/audit_activity/investigation/update_owner.rb
index 59d9aed90d..11567f802e 100644
--- a/psd-web/app/models/audit_activity/investigation/update_owner.rb
+++ b/psd-web/app/models/audit_activity/investigation/update_owner.rb
@@ -1,66 +1,34 @@
 class AuditActivity::Investigation::UpdateOwner < AuditActivity::Investigation::Base
-  include NotifyHelper
-
-  def self.from(investigation)
-    title = investigation.owner.id.to_s
-    body = investigation.owner_rationale
-    super(investigation, title, sanitize_text(body))
-  end
-
-  def owner_id
-    # We store owner_id in title field, this is getting it back
-    # Using alias for accessing parent method causes errors elsewhere :(
-    AuditActivity::Investigation::Base.instance_method(:title).bind(self).call
+  def self.from(*)
+    raise "Deprecated - use ChangeCaseOwner.call instead"
   end
 
-  def title
-    # We store owner_id in title field, this is computing title based on that
-    "Case owner changed to #{(User.find_by(id: owner_id) || Team.find_by(id: owner_id))&.decorate&.display_name}"
+  def self.build_metadata(owner, rationale)
+    {
+      owner_id: owner.id,
+      rationale: rationale
+    }
   end
 
-  def email_update_text(viewer = nil)
-    body = []
-    body << "Case owner changed on #{investigation.case_type} to #{investigation.owner.decorate.display_name(viewer: viewer)} by #{source&.show(viewer)}."
-
-    if investigation.owner_rationale.present?
-      body << "Message from #{source&.show(viewer)}:"
-      body << inset_text_for_notify(investigation.owner_rationale)
-    end
-
-    body.join("\n\n")
+  def title(user)
+    "Case owner changed to #{owner.decorate.display_name(viewer: user)}"
   end
 
-  def email_subject_text
-    "Case owner changed for #{investigation.case_type}"
+  def body
+    metadata["rationale"]
   end
 
 private
 
-  def subtitle_slug
-    "Changed"
+  def owner
+    User.find_by(id: metadata["owner_id"]) || Team.find_by(id: metadata["owner_id"])
   end
 
-  def users_to_notify
-    compute_relevant_entities(model: User, compute_users_from_entity: proc { |user| [user] })
-  end
-
-  def teams_to_notify
-    compute_relevant_entities(model: Team, compute_users_from_entity: proc { |team| team.users })
+  def subtitle_slug
+    "Changed"
   end
 
-  def compute_relevant_entities(model:, compute_users_from_entity:)
-    return [] unless investigation.saved_changes.key?("owner_id")
-
-    previous_owner_id = investigation.saved_changes["owner_id"][0]
-    previous_owner = model.find_by(id: previous_owner_id)
-    new_owner = investigation.owner
-    owner_changed_by = source.user
-
-    old_users = previous_owner.present? ? compute_users_from_entity.call(previous_owner) : []
-    old_entities = previous_owner.present? ? [previous_owner] : []
-    new_entities = new_owner.is_a?(model) ? [new_owner] : []
-    return new_entities if old_users.include? owner_changed_by
-
-    (new_entities + old_entities).uniq
-  end
+  # Do not send investigation_updated mail when case added. This overrides
+  # inherited functionality in the Activity model :(
+  def notify_relevant_users; end
 end
diff --git a/psd-web/app/models/comment_activity.rb b/psd-web/app/models/comment_activity.rb
index cd9b92c896..cc753d64c6 100644
--- a/psd-web/app/models/comment_activity.rb
+++ b/psd-web/app/models/comment_activity.rb
@@ -4,7 +4,7 @@ class CommentActivity < Activity
   validates :body, presence: true
   validates :body, length: { maximum: 10_000 }
 
-  def title
+  def title(_user)
     "Comment added"
   end
 
diff --git a/psd-web/app/models/investigation.rb b/psd-web/app/models/investigation.rb
index bd8bf53d0d..7537f4fec8 100644
--- a/psd-web/app/models/investigation.rb
+++ b/psd-web/app/models/investigation.rb
@@ -20,15 +20,16 @@ class Investigation < ApplicationRecord
   validates :type, presence: true # Prevent saving instances of Investigation; must use a subclass instead
 
   validates :description, presence: true, on: :update
-  validates :owner_id, presence: { message: "Select case owner" }, on: :update
+
+  # Can currently only validate this on update since create case wizards validate Investigation instances
+  validates :owner_id, presence: true, on: :update
 
   validates :user_title, length: { maximum: 100 }
   validates :description, length: { maximum: 10_000 }
   validates :non_compliant_reason, length: { maximum: 10_000 }
   validates :hazard_description, length: { maximum: 10_000 }
 
-  after_update :create_audit_activity_for_owner,
-               :create_audit_activity_for_status,
+  after_update :create_audit_activity_for_status,
                :create_audit_activity_for_visibility,
                :create_audit_activity_for_summary
 
@@ -171,14 +172,6 @@ def create_audit_activity_for_visibility
     end
   end
 
-  def create_audit_activity_for_owner
-    # TODO: User.current check is here to avoid triggering activity and emails from migrations
-    # Can be safely removed once the migration PopulateAssigneeAndDescription has run
-    if ((saved_changes.key? :owner_id) || (saved_changes.key? :owner_type)) && User.current
-      AuditActivity::Investigation::UpdateOwner.from(self)
-    end
-  end
-
   def create_audit_activity_for_summary
     # TODO: User.current check is here to avoid triggering activity and emails from migrations
     # Can be safely removed once the migration PopulateAssigneeAndDescription has run
diff --git a/psd-web/app/services/change_case_owner.rb b/psd-web/app/services/change_case_owner.rb
new file mode 100644
index 0000000000..926be0ac34
--- /dev/null
+++ b/psd-web/app/services/change_case_owner.rb
@@ -0,0 +1,77 @@
+class ChangeCaseOwner
+  include Interactor
+  include NotifyHelper
+
+  delegate :investigation, :owner, :rationale, :user, :old_owner, to: :context
+
+  def call
+    context.fail!(error: "No investigation supplied") unless investigation.is_a?(Investigation)
+    context.fail!(error: "No owner supplied") unless owner.is_a?(User) || owner.is_a?(Team)
+    context.fail!(error: "No user supplied") unless user.is_a?(User)
+
+    context.old_owner = investigation.owner
+
+    if old_owner != owner
+      investigation.owner = owner
+
+      ActiveRecord::Base.transaction do
+        investigation.save!
+
+        create_audit_activity_for_case_owner_changed
+      end
+
+      send_notification_email
+    end
+  end
+
+private
+
+  def create_audit_activity_for_case_owner_changed
+    metadata = activity_class.build_metadata(owner, rationale)
+
+    activity_class.create!(
+      source: UserSource.new(user: user),
+      investigation: investigation,
+      title: nil,
+      body: nil,
+      metadata: metadata
+    )
+  end
+
+  def activity_class
+    AuditActivity::Investigation::UpdateOwner
+  end
+
+  def send_notification_email
+    entities_to_notify.each do |recipient|
+      email = recipient.is_a?(Team) ? recipient.team_recipient_email : recipient.email
+
+      NotifyMailer.investigation_updated(
+        investigation.pretty_id,
+        recipient.name,
+        email,
+        email_body(recipient),
+        "Case owner changed for #{investigation.case_type}"
+      ).deliver_later
+    end
+  end
+
+  # Notify the new owner, and the old one if it's not the user making the change
+  def entities_to_notify
+    entities = [owner]
+    entities << old_owner if old_owner != user
+
+    entities.map { |entity|
+      return entity.users.active if entity.is_a?(Team) && !entity.team_recipient_email
+
+      entity
+    }.flatten.uniq
+  end
+
+  def email_body(viewer = nil)
+    user_name = user.decorate.display_name(viewer: viewer)
+    body = "Case owner changed on #{investigation.case_type} to #{owner.decorate.display_name(viewer: viewer)} by #{user_name}."
+    body << "\n\nMessage from #{user_name}: #{inset_text_for_notify(rationale)}" if rationale
+    body
+  end
+end
diff --git a/psd-web/app/services/delete_user.rb b/psd-web/app/services/delete_user.rb
index e8c28d3e4c..c1328e002f 100644
--- a/psd-web/app/services/delete_user.rb
+++ b/psd-web/app/services/delete_user.rb
@@ -1,12 +1,14 @@
 class DeleteUser
   include Interactor
 
+  delegate :user, to: :context
+
   def call
-    context.fail!(error: "No user supplied") unless context.user
-    context.fail!(error: "User already deleted") if context.user.deleted?
+    context.fail!(error: "No user supplied") unless user.is_a?(User)
+    context.fail!(error: "User already deleted") if user.deleted?
 
     ActiveRecord::Base.transaction do
-      context.user.mark_as_deleted!
+      user.mark_as_deleted!
       change_user_investigations_ownership_to_their_team
     end
   end
@@ -16,10 +18,27 @@ def call
   def change_user_investigations_ownership_to_their_team
     context.team = context.user.team
 
-    context.user.investigations.each do |investigation|
+    user.investigations.each do |investigation|
       investigation.owner = context.team
       investigation.save!
-      AuditActivity::Investigation::AutomaticallyUpdateOwner.from(investigation)
+
+      create_audit_activity_for_case_owner_automatically_changed(investigation)
     end
   end
+
+  def create_audit_activity_for_case_owner_automatically_changed(investigation)
+    metadata = activity_class.build_metadata(investigation.owner)
+
+    activity_class.create!(
+      source: nil, # DeleteUser is called from rake user:delete where no user source is available
+      investigation: investigation,
+      title: nil,
+      body: nil,
+      metadata: metadata
+    )
+  end
+
+  def activity_class
+    AuditActivity::Investigation::AutomaticallyUpdateOwner
+  end
 end
diff --git a/psd-web/app/views/investigations/activities/_activity_card.html.erb b/psd-web/app/views/investigations/activities/_activity_card.html.erb
index f4232c1036..4eba9a9ec2 100644
--- a/psd-web/app/views/investigations/activities/_activity_card.html.erb
+++ b/psd-web/app/views/investigations/activities/_activity_card.html.erb
@@ -1,12 +1,12 @@
 <%
   restricted = !activity.can_display_all_data?(current_user)
-  title = restricted ? activity.restricted_title : activity.title
+  title = restricted ? activity.restricted_title(current_user) : activity.title(current_user)
 %>
 
 <li>
   <h3 class="govuk-heading-s"><%= title %></h3>
 
-  <p class="govuk-body-s timeline-details"><%= activity.subtitle %></p>
+  <p class="govuk-body-s timeline-details"><%= activity.subtitle(current_user) %></p>
 
   <% if restricted %>
     <%= render "restricted", activity: activity %>
diff --git a/psd-web/app/views/investigations/activities/investigation/_update_owner.html.erb b/psd-web/app/views/investigations/activities/investigation/_update_owner.html.erb
new file mode 100644
index 0000000000..4854ec1e62
--- /dev/null
+++ b/psd-web/app/views/investigations/activities/investigation/_update_owner.html.erb
@@ -0,0 +1 @@
+<%= markdown simple_format(activity.metadata["rationale"]) %>
diff --git a/psd-web/config/locales/en.yml b/psd-web/config/locales/en.yml
index cc56107760..456f2910f1 100644
--- a/psd-web/config/locales/en.yml
+++ b/psd-web/config/locales/en.yml
@@ -129,6 +129,10 @@ en:
   activemodel:
     errors:
       models:
+        change_case_owner_form:
+          attributes:
+            owner_id:
+              not_found: Select case owner
         invite_user_to_team_form:
           attributes:
             email:
diff --git a/psd-web/lib/tasks/move_update_owner_activity_metadata.rb b/psd-web/lib/tasks/move_update_owner_activity_metadata.rb
new file mode 100644
index 0000000000..4116047cb5
--- /dev/null
+++ b/psd-web/lib/tasks/move_update_owner_activity_metadata.rb
@@ -0,0 +1,38 @@
+desc "One-time task to move AuditActivity::Investigation::UpdateOwner metadata to metadata column"
+task move_update_owner_activity_metadata: :environment do
+  klass = AuditActivity::Investigation::UpdateOwner
+
+  ActiveRecord::Base.transaction do
+    klass.all.each do |activity|
+      next if activity.metadata
+
+      # case owner ID is stored in the title column...
+      next unless (owner_id = activity.title)
+
+      owner = User.find_by(id: owner_id) || Team.find_by(id: owner_id)
+
+      metadata = klass.build_metadata(owner, activity.body)
+
+      activity.update!(metadata: metadata, title: nil, body: nil)
+    end
+  end
+
+  klass = AuditActivity::Investigation::AutomaticallyUpdateOwner
+
+  ActiveRecord::Base.transaction do
+    klass.all.each do |activity|
+      next if activity.metadata
+
+      # case owner ID is stored in the title column...
+      next unless (owner_id = activity.title)
+
+      owner = User.find_by(id: owner_id) || Team.find_by(id: owner_id)
+
+      metadata = klass.build_metadata(owner)
+
+      activity.update!(metadata: metadata, title: nil, body: nil)
+    end
+  end
+
+  puts "Done."
+end
diff --git a/psd-web/spec/features/change_ownership_for_investigation_spec.rb b/psd-web/spec/features/change_ownership_for_investigation_spec.rb
index ab462a42c6..e618108125 100644
--- a/psd-web/spec/features/change_ownership_for_investigation_spec.rb
+++ b/psd-web/spec/features/change_ownership_for_investigation_spec.rb
@@ -12,7 +12,7 @@
 
   before do
     sign_in(user)
-    visit "/cases/#{investigation.pretty_id}/assign/select-owner"
+    visit "/cases/#{investigation.pretty_id}/assign/new"
   end
 
   scenario "does not show inactive users" do
diff --git a/psd-web/spec/features/record_email_activity_spec.rb b/psd-web/spec/features/record_email_activity_spec.rb
index 8c5f809b23..06113b06e7 100644
--- a/psd-web/spec/features/record_email_activity_spec.rb
+++ b/psd-web/spec/features/record_email_activity_spec.rb
@@ -81,7 +81,7 @@
     expect_to_be_on_case_activity_page(case_id: investigation.pretty_id)
 
     # Consumer info is not hidden from case owner
-    expect_case_activity_page_to_show_entered_information(name: name, email: email, date: date, file: file)
+    expect_case_activity_page_to_show_entered_information(user_name: user.name, name: name, email: email, date: date, file: file)
 
     click_link "View email"
 
@@ -109,7 +109,7 @@
     visit "/cases/#{investigation.pretty_id}/activity"
 
     expect_to_be_on_case_activity_page(case_id: investigation.pretty_id)
-    expect_case_activity_page_to_show_entered_information(name: name, email: email, date: date, file: file)
+    expect_case_activity_page_to_show_entered_information(user_name: user.name, name: name, email: email, date: date, file: file)
   end
 
   scenario "with non-consumer contact details and summary and subject and body" do
@@ -135,7 +135,7 @@
     click_on "Activity"
 
     expect_to_be_on_case_activity_page(case_id: investigation.pretty_id)
-    expect_case_activity_page_to_show_entered_information(name: name, email: email, date: date, summary: summary, subject: email_subject, body: body)
+    expect_case_activity_page_to_show_entered_information(user_name: user.name, name: name, email: email, date: date, summary: summary, subject: email_subject, body: body)
 
     # Test that another user in a different organisation can see all info
     sign_out
@@ -145,7 +145,7 @@
     visit "/cases/#{investigation.pretty_id}/activity"
 
     expect_to_be_on_case_activity_page(case_id: investigation.pretty_id)
-    expect_case_activity_page_to_show_entered_information(name: name, email: email, date: date, summary: summary, subject: email_subject, body: body)
+    expect_case_activity_page_to_show_entered_information(user_name: "#{user.name} (#{user.team.name})", name: name, email: email, date: date, summary: summary, subject: email_subject, body: body)
   end
 
   def fill_in_record_email_form(name:, email:, consumer:, date:)
@@ -198,8 +198,8 @@ def expect_record_email_form_to_have_entered_information(name:, email:, consumer
     expect(find_field("Year").value).to eq date.year.to_s
   end
 
-  def expect_case_activity_page_to_show_entered_information(name:, email:, date:, file: nil, summary: nil, subject: nil, body: nil)
-    item = page.find("p", text: "Email recorded by #{user.name} (#{user.team.name})").find(:xpath, "..")
+  def expect_case_activity_page_to_show_entered_information(user_name:, name:, email:, date:, file: nil, summary: nil, subject: nil, body: nil)
+    item = page.find("p", text: "Email recorded by #{user_name}").find(:xpath, "..")
     expect(item).to have_text("From: #{name} (#{email})")
     expect(item).to have_text("Date sent: #{date.strftime('%d/%m/%Y')}")
 
diff --git a/psd-web/spec/features/record_phone_call_activity_spec.rb b/psd-web/spec/features/record_phone_call_activity_spec.rb
index d7dfc2fb9f..175436d6fa 100644
--- a/psd-web/spec/features/record_phone_call_activity_spec.rb
+++ b/psd-web/spec/features/record_phone_call_activity_spec.rb
@@ -78,7 +78,7 @@
     expect_to_be_on_case_activity_page(case_id: investigation.pretty_id)
 
     # Consumer info is not hidden from case owner
-    expect_case_activity_page_to_show_entered_information(name: name, phone: phone, date: date, file: file)
+    expect_case_activity_page_to_show_entered_information(user_name: user.name, name: name, phone: phone, date: date, file: file)
 
     click_link "View phone call"
 
@@ -106,7 +106,7 @@
     visit "/cases/#{investigation.pretty_id}/activity"
 
     expect_to_be_on_case_activity_page(case_id: investigation.pretty_id)
-    expect_case_activity_page_to_show_entered_information(name: name, phone: phone, date: date, file: file)
+    expect_case_activity_page_to_show_entered_information(user_name: user.name, name: name, phone: phone, date: date, file: file)
   end
 
   scenario "with non-consumer contact details and summary and notes" do
@@ -132,7 +132,7 @@
     click_on "Activity"
 
     expect_to_be_on_case_activity_page(case_id: investigation.pretty_id)
-    expect_case_activity_page_to_show_entered_information(name: name, phone: phone, date: date, summary: summary, notes: notes)
+    expect_case_activity_page_to_show_entered_information(user_name: user.name, name: name, phone: phone, date: date, summary: summary, notes: notes)
 
     # Test that another user in a different organisation can see all info
     sign_out
@@ -142,7 +142,7 @@
     visit "/cases/#{investigation.pretty_id}/activity"
 
     expect_to_be_on_case_activity_page(case_id: investigation.pretty_id)
-    expect_case_activity_page_to_show_entered_information(name: name, phone: phone, date: date, summary: summary, notes: notes)
+    expect_case_activity_page_to_show_entered_information(user_name: "#{user.name} (#{user.team.name})", name: name, phone: phone, date: date, summary: summary, notes: notes)
   end
 
   def fill_in_record_phone_call_form(name:, phone:, consumer:, date:)
@@ -189,8 +189,8 @@ def expect_record_phone_call_form_to_have_entered_information(name:, phone:, con
     expect(find_field("Year").value).to eq date.year.to_s
   end
 
-  def expect_case_activity_page_to_show_entered_information(name:, phone:, date:, file: nil, summary: nil, notes: nil)
-    item = page.find("p", text: "Phone call by #{user.name} (#{user.team.name})").find(:xpath, "..")
+  def expect_case_activity_page_to_show_entered_information(user_name:, name:, phone:, date:, file: nil, summary: nil, notes: nil)
+    item = page.find("p", text: "Phone call by #{user_name}").find(:xpath, "..")
     expect(item).to have_text("Call with: #{name} (#{phone})")
     expect(item).to have_text("Date: #{date.strftime('%d/%m/%Y')}")
 
diff --git a/psd-web/spec/forms/edit_investigation_collaborator_form_spec.rb b/psd-web/spec/forms/edit_investigation_collaborator_form_spec.rb
index 8e5e1bfb67..ca0df213f2 100644
--- a/psd-web/spec/forms/edit_investigation_collaborator_form_spec.rb
+++ b/psd-web/spec/forms/edit_investigation_collaborator_form_spec.rb
@@ -72,7 +72,7 @@
 
           last_added_activity = investigation.activities.reload.order(created_at: :desc)
             .find_by!(type: "AuditActivity::Investigation::TeamDeleted")
-          expect(last_added_activity.title).to eql("test team removed from allegation")
+          expect(last_added_activity.title(user)).to eql("test team removed from allegation")
           expect(last_added_activity.source.user_id).to eql(user.id)
         end
       end
diff --git a/psd-web/spec/models/audit_activity/investigation/automatically_update_owner_spec.rb b/psd-web/spec/models/audit_activity/investigation/automatically_update_owner_spec.rb
deleted file mode 100644
index 67614dd4f4..0000000000
--- a/psd-web/spec/models/audit_activity/investigation/automatically_update_owner_spec.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-require "rails_helper"
-
-RSpec.describe AuditActivity::Investigation::AutomaticallyUpdateOwner, :with_stubbed_mailer, :with_stubbed_elasticsearch do
-  subject(:audit_activity) { described_class.from(investigation) }
-
-  let(:team) { create(:team) }
-  let(:investigation) { create(:enquiry, owner: team, owner_rationale: "Test owner") }
-
-  describe ".from" do
-    it "creates an audit activity without information for email notification" do
-      expect(audit_activity).to have_attributes(
-        title: "Case owner automatically changed on Enquiry to #{team.display_name}",
-        body: nil,
-        email_update_text: nil,
-        email_subject_text: nil
-      )
-    end
-  end
-end
diff --git a/psd-web/spec/models/audit_activity/investigation/update_coronavirus_status_spec.rb b/psd-web/spec/models/audit_activity/investigation/update_coronavirus_status_spec.rb
index f8e52d215b..f4a729f816 100644
--- a/psd-web/spec/models/audit_activity/investigation/update_coronavirus_status_spec.rb
+++ b/psd-web/spec/models/audit_activity/investigation/update_coronavirus_status_spec.rb
@@ -11,10 +11,10 @@
   describe ".from" do
     it "creates an audit activity", :aggregate_failures do
       expect(audit_activity).to have_attributes(
-        title: "Status updated: not coronavirus related",
         body: "The case is not related to the coronavirus outbreak.",
         email_subject_text: "Coronavirus status updated on #{investigation.case_type.downcase}"
       )
+      expect(audit_activity.title(user)).to eq("Status updated: not coronavirus related")
       expect(audit_activity.email_update_text(user)).to eq("#{investigation.case_type.capitalize} #{investigation.pretty_id} is not related to the coronavirus outbreak. This status was updated by #{user.name}.")
     end
   end
diff --git a/psd-web/spec/models/audit_activity/investigation/update_owner_spec.rb b/psd-web/spec/models/audit_activity/investigation/update_owner_spec.rb
deleted file mode 100644
index 52febdf944..0000000000
--- a/psd-web/spec/models/audit_activity/investigation/update_owner_spec.rb
+++ /dev/null
@@ -1,21 +0,0 @@
-require "rails_helper"
-
-RSpec.describe AuditActivity::Investigation::UpdateOwner, :with_stubbed_mailer, :with_stubbed_elasticsearch do
-  subject(:audit_activity) { described_class.from(investigation) }
-
-  let(:user) { create(:user).decorate }
-  let(:investigation) { create(:enquiry, owner: user, owner_rationale: "Test owner") }
-
-  before { User.current = user }
-
-  describe ".from" do
-    it "creates an audit activity with information for email notification", :aggregate_failures do
-      expect(audit_activity).to have_attributes(
-        title: "Case owner changed to #{user.display_name}",
-        body: investigation.owner_rationale,
-        email_subject_text: "Case owner changed for enquiry"
-      )
-      expect(audit_activity.email_update_text(user)).to start_with("Case owner changed on enquiry to #{user.name} by #{user.name}")
-    end
-  end
-end
diff --git a/psd-web/spec/services/add_product_to_case_spec.rb b/psd-web/spec/services/add_product_to_case_spec.rb
index 2b067b83ea..7297fe7a57 100644
--- a/psd-web/spec/services/add_product_to_case_spec.rb
+++ b/psd-web/spec/services/add_product_to_case_spec.rb
@@ -59,7 +59,7 @@
         expect(activity).to be_a(AuditActivity::Product::Add)
         expect(activity.source.user).to eq(user)
         expect(activity.product_id).to eq(product.id)
-        expect(activity.title).to eq(product.name)
+        expect(activity.title(nil)).to eq(product.name)
       end
 
       context "when the case owner is a user" do
diff --git a/psd-web/spec/services/add_team_to_an_investigation_spec.rb b/psd-web/spec/services/add_team_to_an_investigation_spec.rb
index 4213bc7d9e..cbce7adbb8 100644
--- a/psd-web/spec/services/add_team_to_an_investigation_spec.rb
+++ b/psd-web/spec/services/add_team_to_an_investigation_spec.rb
@@ -51,7 +51,7 @@
 
         aggregate_failures do
           expect(last_added_activity).to be_a(AuditActivity::Investigation::TeamAdded)
-          expect(last_added_activity.title).to eql("Testing team added to allegation")
+          expect(last_added_activity.title(nil)).to eql("Testing team added to allegation")
           expect(last_added_activity.source.user_id).to eql(user.id)
         end
       end
diff --git a/psd-web/spec/services/create_case_spec.rb b/psd-web/spec/services/create_case_spec.rb
index 8f80ae8d65..ac34727fe9 100644
--- a/psd-web/spec/services/create_case_spec.rb
+++ b/psd-web/spec/services/create_case_spec.rb
@@ -77,7 +77,7 @@
           expect(activity).to be_a(AuditActivity::Product::Add)
           expect(activity.source.user).to eq(user)
           expect(activity.product_id).to eq(product.id)
-          expect(activity.title).to eq(product.name)
+          expect(activity.title(user)).to eq(product.name)
         end
       end
 
diff --git a/psd-web/spec/services/delete_user_spec.rb b/psd-web/spec/services/delete_user_spec.rb
index fe63390a2c..60848142d2 100644
--- a/psd-web/spec/services/delete_user_spec.rb
+++ b/psd-web/spec/services/delete_user_spec.rb
@@ -67,8 +67,8 @@
         expect { delete_call }.to change(update_owner_activities, :count).by(3)
 
         update_owner_activities.last(3).each do |activity|
-          expect(activity.title).to start_with "Case owner automatically changed on"
-          expect(activity.title).to end_with "to #{user.team.display_name}"
+          expect(activity.title(user)).to start_with "Case owner automatically changed on"
+          expect(activity.title(user)).to end_with "to #{user.team.name}"
         end
       end
       # rubocop:enable RSpec/ExampleLength
diff --git a/psd-web/spec/services/remove_product_from_case_spec.rb b/psd-web/spec/services/remove_product_from_case_spec.rb
index eeabbbf297..ed9bed5ad7 100644
--- a/psd-web/spec/services/remove_product_from_case_spec.rb
+++ b/psd-web/spec/services/remove_product_from_case_spec.rb
@@ -59,7 +59,7 @@
         expect(activity).to be_a(AuditActivity::Product::Destroy)
         expect(activity.source.user).to eq(user)
         expect(activity.product_id).to eq(product.id)
-        expect(activity.title).to eq("Removed: #{product.name}")
+        expect(activity.title(nil)).to eq("Removed: #{product.name}")
       end
 
       context "when the case owner is a user" do
diff --git a/psd-web/spec/support/audit_activity_investigation.rb b/psd-web/spec/support/audit_activity_investigation.rb
index 35b69791c3..2c4c96b0e0 100644
--- a/psd-web/spec/support/audit_activity_investigation.rb
+++ b/psd-web/spec/support/audit_activity_investigation.rb
@@ -95,7 +95,7 @@
   end
 
   describe "#title" do
-    subject(:title) { activity.title }
+    subject(:title) { activity.title(nil) }
 
     let(:activity) { described_class.create(investigation: investigation, metadata: metadata, title: test_title) }
     let(:test_title) { nil }
@@ -170,14 +170,14 @@
   end
 
   describe "#restricted_title" do
-    # This metod will only ever be called for older records with no metadata,
+    # This method will only ever be called for older records with no metadata,
     # where the title is pre-generated and stored in the database, so we will
     # set the title here
     subject(:activity) { described_class.create(investigation: investigation, title: "Test title") }
 
     # titles never contain GDPR data for these activity classes so just return the title
     it "returns the title" do
-      expect(activity.restricted_title).to eq("Test title")
+      expect(activity.restricted_title(nil)).to eq("Test title")
     end
   end
 end