diff --git a/app/services/update_user.rb b/app/services/update_user.rb
index ea887f5df98..0ba47d6c107 100644
--- a/app/services/update_user.rb
+++ b/app/services/update_user.rb
@@ -21,7 +21,7 @@ def call
 
   def manage_phone_configuration
     if attributes[:phone_id].present?
-      update_phone_configuration
+      update_phone_configuration unless phone_configuration.nil?
     else
       create_phone_configuration
     end
diff --git a/spec/services/update_user_spec.rb b/spec/services/update_user_spec.rb
index b1d43fbeb81..7c15f91ed52 100644
--- a/spec/services/update_user_spec.rb
+++ b/spec/services/update_user_spec.rb
@@ -127,6 +127,16 @@
             to be_within(1.second).of original_made_default_at
         end
       end
+
+      context 'when phone does not belong to user' do
+        it 'does not update the user if the phone does not belong to them' do
+          other_phone = create(:phone_configuration)
+          attributes[:phone_id] = other_phone.id
+          expect do
+            UpdateUser.new(user: user, attributes: attributes).call
+          end.to_not(change { other_phone.updated_at })
+        end
+      end
     end
   end
 end