diff --git a/app/models/log.rb b/app/models/log.rb
index 1012f60ee..17f372db0 100644
--- a/app/models/log.rb
+++ b/app/models/log.rb
@@ -82,7 +82,7 @@ class Log < ApplicationRecord
       service = AddressClient.new(address_string)
       service.call
 
-      return errors.add(:address_line1_input, :address_error, message: service.error) if service.error.present?
+      return errors.add(:address_selection, :address_error, message: service.error) if service.error.present?
 
       if address_selection.between?(0, 9)
         presenter = AddressDataPresenter.new(service.result[address_selection])
diff --git a/spec/shared/shared_log_examples.rb b/spec/shared/shared_log_examples.rb
index 354a8b1ee..7202544ba 100644
--- a/spec/shared/shared_log_examples.rb
+++ b/spec/shared/shared_log_examples.rb
@@ -106,5 +106,67 @@ RSpec.shared_examples "shared log examples" do |log_type|
       end
     end
   end
+
+  describe "#process_address_change!" do
+    context "when address_line1_input and postcode_full_input set to a value" do
+      let(:log) do
+        log = build(
+          log_type,
+          address_selection: 0,
+          address_line1: "Address line 1",
+          postcode_full: "AA1 1AA",
+          county: "county",
+        )
+        log.save!(validate: false)
+        log
+      end
+
+      it "updates log fields" do
+        log.address_line1_input = "New address line 1"
+        log.postcode_full_input = "BB2 2BB"
+
+        allow_any_instance_of(AddressClient).to receive(:call)
+        allow_any_instance_of(AddressClient).to receive(:result).and_return([{
+          "UPRN" => "UPRN",
+          "UDPRN" => "UDPRN",
+          "ADDRESS" => "full address",
+          "SUB_BUILDING_NAME" => "0",
+          "BUILDING_NAME" => "building name",
+          "THOROUGHFARE_NAME" => "thoroughfare",
+          "POST_TOWN" => "posttown",
+          "POSTCODE" => "postcode",
+        }])
+
+        expect { log.process_address_change! }.to change(log, :address_line1).from("Address line 1").to("0, Building Name, Thoroughfare")
+                                              .and change(log, :town_or_city).from(nil).to("Posttown")
+                                              .and change(log, :postcode_full).from("AA1 1AA").to("POSTCODE")
+                                              .and change(log, :uprn_confirmed).from(nil).to(1)
+                                              .and change(log, :uprn).from(nil).to("UPRN")
+                                              .and change(log, :uprn_known).from(nil).to(1)
+                                              .and change(log, :address_selection).from(0).to(nil)
+                                              .and change(log, :county).from("county").to(nil)
+      end
+    end
+
+    context "when address inputs are nil" do
+      let(:log) { create(log_type, address_selection: nil, address_line1_input: nil, postcode_full_input: nil) }
+
+      it "does not update log" do
+        expect { log.process_address_change! }.not_to change(log, :attributes)
+      end
+    end
+
+    context "when service errors" do
+      let(:log) { build(log_type, :in_progress, address_selection: 0, address_line1_input: "123", postcode_full_input: "AA1 1AA") }
+      let(:error_message) { "error" }
+
+      it "adds error to log" do
+        allow_any_instance_of(AddressClient).to receive(:call)
+        allow_any_instance_of(AddressClient).to receive(:error).and_return(error_message)
+
+        expect { log.process_address_change! }.to change { log.errors[:address_selection] }.from([]).to([error_message])
+      end
+    end
+  end
 end
 # rubocop:enable RSpec/AnyInstance