diff --git a/app/controllers/duplicate_logs_controller.rb b/app/controllers/duplicate_logs_controller.rb
index e08ec828d..9539494c0 100644
--- a/app/controllers/duplicate_logs_controller.rb
+++ b/app/controllers/duplicate_logs_controller.rb
@@ -28,7 +28,7 @@ private
 
   def duplicate_check_question_ids
     if @log.lettings?
-      %w[owning_organisation_id startdate tenancycode postcode_full age1 sex1 ecstat1 tcharge]
+      ["owning_organisation_id", "startdate", "tenancycode", @log.is_general_needs? ? "postcode_full" : nil, @log.is_supported_housing? ? "location_id" : nil, "age1", "sex1", "ecstat1", "tcharge"].compact
     else
       %w[owning_organisation_id saledate purchid age1 sex1 ecstat1 postcode_full]
     end
diff --git a/app/models/lettings_log.rb b/app/models/lettings_log.rb
index 6f3ce1cec..d93a173f9 100644
--- a/app/models/lettings_log.rb
+++ b/app/models/lettings_log.rb
@@ -56,8 +56,9 @@ class LettingsLog < Log
   scope :duplicate_logs, lambda { |log|
     visible.where(log.slice(*DUPLICATE_LOG_ATTRIBUTES))
     .where.not(id: log.id)
-    .where.not("startdate IS NULL OR age1 IS NULL OR sex1 IS NULL OR ecstat1 IS NULL OR tcharge IS NULL OR postcode_full IS NULL OR needstype IS NULL")
+    .where.not("startdate IS NULL OR age1 IS NULL OR sex1 IS NULL OR ecstat1 IS NULL OR tcharge IS NULL OR needstype IS NULL")
     .where("location_id = ? OR needstype = 1", log.location_id)
+    .where("postcode_full = ? OR needstype = 2", log.postcode_full)
   }
 
   AUTOGENERATED_FIELDS = %w[id status created_at updated_at discarded_at].freeze
@@ -67,7 +68,7 @@ class LettingsLog < Log
   NUM_OF_WEEKS_FROM_PERIOD = { 2 => 26, 3 => 13, 4 => 12, 5 => 50, 6 => 49, 7 => 48, 8 => 47, 9 => 46, 1 => 52, 10 => 53 }.freeze
   SUFFIX_FROM_PERIOD = { 2 => "every 2 weeks", 3 => "every 4 weeks", 4 => "every month" }.freeze
   RETIREMENT_AGES = { "M" => 67, "F" => 60, "X" => 67 }.freeze
-  DUPLICATE_LOG_ATTRIBUTES = %w[tenancycode startdate age1 sex1 ecstat1 tcharge postcode_full].freeze
+  DUPLICATE_LOG_ATTRIBUTES = %w[tenancycode startdate age1 sex1 ecstat1 tcharge].freeze
 
   def form
     FormHandler.instance.get_form(form_name) || FormHandler.instance.current_lettings_form