diff --git a/app/models/organisation.rb b/app/models/organisation.rb
index fd8891961..32d3540d1 100644
--- a/app/models/organisation.rb
+++ b/app/models/organisation.rb
@@ -58,6 +58,10 @@ class Organisation < ApplicationRecord
     end
   end
 
+  def can_be_managed_by?(organisation:)
+    organisation == self || managing_agents.include?(organisation)
+  end
+
   def lettings_logs
     LettingsLog.filter_by_organisation(self)
   end
diff --git a/app/services/bulk_upload/lettings/row_parser.rb b/app/services/bulk_upload/lettings/row_parser.rb
index ca86a48a1..bdb35dbc6 100644
--- a/app/services/bulk_upload/lettings/row_parser.rb
+++ b/app/services/bulk_upload/lettings/row_parser.rb
@@ -117,7 +117,7 @@ class BulkUpload::Lettings::RowParser
   attribute :field_110
   attribute :field_111, :string
   attribute :field_112, :string
-  attribute :field_113, :integer
+  attribute :field_113, :string
   attribute :field_114, :integer
   attribute :field_115
   attribute :field_116, :integer
@@ -155,10 +155,14 @@ class BulkUpload::Lettings::RowParser
   validate :validate_no_disabled_needs_conjunction
   validate :validate_dont_know_disabled_needs_conjunction
   validate :validate_no_and_dont_know_disabled_needs_conjunction
+
   validate :validate_owning_org_permitted
   validate :validate_owning_org_owns_stock
   validate :validate_owning_org_exists
 
+  validate :validate_managing_org_related
+  validate :validate_managing_org_exists
+
   def valid?
     errors.clear
 
@@ -194,6 +198,20 @@ class BulkUpload::Lettings::RowParser
 
 private
 
+  def validate_managing_org_related
+    if owning_organisation && managing_organisation && !owning_organisation.can_be_managed_by?(organisation: managing_organisation)
+      block_log_creation!
+      errors.add(:field_113, "This managing organisation does not have a relationship with the owning organisation")
+    end
+  end
+
+  def validate_managing_org_exists
+    if managing_organisation.nil?
+      errors.delete(:field_113)
+      errors.add(:field_113, "The managing organisation code is incorrect")
+    end
+  end
+
   def validate_owning_org_owns_stock
     if owning_organisation && !owning_organisation.holds_own_stock?
       block_log_creation!
@@ -525,8 +543,12 @@ private
     owning_organisation&.id
   end
 
+  def managing_organisation
+    Organisation.find_by_id_on_mulitple_fields(field_113)
+  end
+
   def managing_organisation_id
-    Organisation.find_by(old_visible_id: field_113)&.id
+    managing_organisation&.id
   end
 
   def attributes_for_log
diff --git a/spec/services/bulk_upload/lettings/row_parser_spec.rb b/spec/services/bulk_upload/lettings/row_parser_spec.rb
index 341e197f3..36f145a5e 100644
--- a/spec/services/bulk_upload/lettings/row_parser_spec.rb
+++ b/spec/services/bulk_upload/lettings/row_parser_spec.rb
@@ -8,8 +8,10 @@ RSpec.describe BulkUpload::Lettings::RowParser do
   let(:attributes) { { bulk_upload: } }
   let(:bulk_upload) { create(:bulk_upload, :lettings, user:) }
   let(:user) { create(:user, organisation: owning_org) }
+
   let(:owning_org) { create(:organisation, :with_old_visible_id) }
   let(:managing_org) { create(:organisation, :with_old_visible_id) }
+
   let(:setup_section_params) do
     {
       bulk_upload:,
@@ -23,6 +25,10 @@ RSpec.describe BulkUpload::Lettings::RowParser do
     }
   end
 
+  before do
+    create(:organisation_relationship, parent_organisation: owning_org, child_organisation: managing_org)
+  end
+
   around do |example|
     FormHandler.instance.use_real_forms!
 
@@ -510,6 +516,30 @@ RSpec.describe BulkUpload::Lettings::RowParser do
       end
     end
 
+    describe "#field_113" do # managing org
+      context "when cannot find managing org" do
+        let(:attributes) { { bulk_upload:, field_113: "donotexist" } }
+
+        it "is not permitted" do
+          expect(parser.errors[:field_113]).to eql(["The managing organisation code is incorrect"])
+        end
+      end
+
+      context "when not affiliated with managing org" do
+        let(:unaffiliated_org) { create(:organisation, :with_old_visible_id) }
+
+        let(:attributes) { { bulk_upload:, field_111: owning_org.old_visible_id, field_113: unaffiliated_org.old_visible_id } }
+
+        it "is not permitted" do
+          expect(parser.errors[:field_113]).to eql(["This managing organisation does not have a relationship with the owning organisation"])
+        end
+
+        it "blocks log creation" do
+          expect(parser).to be_block_log_creation
+        end
+      end
+    end
+
     describe "#field_134" do
       context "when an unpermitted value" do
         let(:attributes) { { bulk_upload:, field_134: 3 } }
@@ -554,6 +584,16 @@ RSpec.describe BulkUpload::Lettings::RowParser do
       end
     end
 
+    describe "#managing_organisation" do
+      context "when lookup is via id prefixed with ORG" do
+        let(:attributes) { { bulk_upload:, field_113: "ORG#{managing_org.id}" } }
+
+        it "assigns the correct org" do
+          expect(parser.log.managing_organisation).to eql(managing_org)
+        end
+      end
+    end
+
     describe "#cbl" do
       context "when field_75 is yes ie 1" do
         let(:attributes) { { bulk_upload:, field_75: 1 } }