diff --git a/Gemfile b/Gemfile
index 941211367..1b35ac451 100644
--- a/Gemfile
+++ b/Gemfile
@@ -48,6 +48,7 @@ gem 'rack-cors', '~> 1.0', '>= 1.0.2', :require => 'rack/cors'
 gem 'strip_attributes', '~> 1.8'
 gem 'slack-notifier', '~> 2.1'
 gem 'mini_magick', '~> 4.8'
+gem 'elasticsearch', '~> 6.8'
 gem 'elasticsearch-model', '~> 6.0.0', require: 'elasticsearch/model'
 gem 'elasticsearch-rails', '~> 6.0.0'
 gem 'faraday_middleware-aws-sigv4', '~> 0.2.4'
diff --git a/Gemfile.lock b/Gemfile.lock
index b10bef74e..0567afbcb 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -65,8 +65,8 @@ GEM
     audited (4.8.0)
       activerecord (>= 4.0, < 5.3)
     aws-eventstream (1.0.3)
-    aws-partitions (1.165.0)
-    aws-sdk-core (3.53.0)
+    aws-partitions (1.166.0)
+    aws-sdk-core (3.53.1)
       aws-eventstream (~> 1.0, >= 1.0.2)
       aws-partitions (~> 1.0)
       aws-sigv4 (~> 1.1)
@@ -188,10 +188,10 @@ GEM
       sxp (~> 1.0)
     edtf (3.0.4)
       activesupport (>= 3.0, < 6.0)
-    elasticsearch (7.1.0)
-      elasticsearch-api (= 7.1.0)
-      elasticsearch-transport (= 7.1.0)
-    elasticsearch-api (7.1.0)
+    elasticsearch (6.8.0)
+      elasticsearch-api (= 6.8.0)
+      elasticsearch-transport (= 6.8.0)
+    elasticsearch-api (6.8.0)
       multi_json
     elasticsearch-extensions (0.0.31)
       ansi
@@ -201,7 +201,7 @@ GEM
       elasticsearch (> 1)
       hashie
     elasticsearch-rails (6.0.0)
-    elasticsearch-transport (7.1.0)
+    elasticsearch-transport (6.8.0)
       faraday
       multi_json
     equivalent-xml (0.6.0)
@@ -554,6 +554,7 @@ DEPENDENCIES
   database_cleaner
   diffy (~> 3.2, >= 3.2.1)
   dotenv
+  elasticsearch (~> 6.8)
   elasticsearch-extensions (~> 0.0.29)
   elasticsearch-model (~> 6.0.0)
   elasticsearch-rails (~> 6.0.0)
diff --git a/app/jobs/delete_job.rb b/app/jobs/delete_job.rb
new file mode 100644
index 000000000..4c690eaa0
--- /dev/null
+++ b/app/jobs/delete_job.rb
@@ -0,0 +1,15 @@
+class DeleteJob < ActiveJob::Base
+  queue_as :lupo_background
+
+  def perform(doi_id, options={})
+    logger = Logger.new(STDOUT)
+    doi = Doi.where(doi: doi_id).first
+
+    if doi.present?
+      doi.destroy
+      logger.info "Deleted DOI " + doi_id + "."
+    else
+      logger.info "Error deleting DOI " + doi_id + ": not found"
+    end
+  end
+end
diff --git a/app/jobs/transfer_job.rb b/app/jobs/transfer_job.rb
index d23ae6e15..a2ffbfc4e 100644
--- a/app/jobs/transfer_job.rb
+++ b/app/jobs/transfer_job.rb
@@ -22,4 +22,4 @@ def perform(doi_id, options={})
       logger.info "[Transfer] Error transferring DOI " + doi_id + ": not found"
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/models/concerns/indexable.rb b/app/models/concerns/indexable.rb
index 766c24271..5989fa9b8 100644
--- a/app/models/concerns/indexable.rb
+++ b/app/models/concerns/indexable.rb
@@ -142,7 +142,7 @@ def query(query, options={})
       must << { term: { "types.resourceTypeGeneral": options[:resource_type_id].underscore.camelize }} if options[:resource_type_id].present?
       must << { terms: { provider_id: options[:provider_id].split(",") }} if options[:provider_id].present?
       must << { terms: { client_id: options[:client_id].to_s.split(",") }} if options[:client_id].present?
-      must << { term: { prefix: options[:prefix] }} if options[:prefix].present?
+      must << { terms: { prefix: options[:prefix].to_s.split(",") }} if options[:prefix].present?
       must << { term: { uid: options[:uid] }} if options[:uid].present?
       must << { term: { "author.id" => "https://orcid.org/#{options[:person_id]}" }} if options[:person_id].present?
       must << { range: { created: { gte: "#{options[:created].split(",").min}||/y", lte: "#{options[:created].split(",").max}||/y", format: "yyyy" }}} if options[:created].present?
diff --git a/app/models/doi.rb b/app/models/doi.rb
index b1a900459..69ea83ca1 100644
--- a/app/models/doi.rb
+++ b/app/models/doi.rb
@@ -871,13 +871,39 @@ def self.delete_test_dois(from_date: nil)
     end
   end
 
-  #to be used after DOIS transfer to another RA
-  def self.delete_dois_by_prefix(prefix)
-    collection.where("doi LIKE ?", prefix).find_each do |d|
-      logger = Logger.new(STDOUT)
-      logger.info "Deleted #{d.doi}, last updated #{d.updated.iso8601}."
-      d.destroy
+  # to be used after DOIs were transferred to another DOI RA
+  def self.delete_dois_by_prefix(prefix, options={})
+    logger = Logger.new(STDOUT)
+
+    if prefix.blank?
+      Logger.error "[Error] No prefix provided."
+      return nil
     end
+
+    # query = options[:query] || "*"
+    size = (options[:size] || 1000).to_i
+
+    response = Doi.query(nil, prefix: prefix, page: { size: 1, cursor: 0 })
+    logger.info "#{response.results.total} DOIs found for prefix #{prefix}."
+
+    if prefix && response.results.total > 0
+      # walk through results using cursor
+      cursor = 0
+
+      while response.results.results.length > 0 do
+        response = Doi.query(nil, prefix: prefix, page: { size: size, cursor: cursor })
+        break unless response.results.results.length > 0
+
+        logger.info "Deleting #{response.results.results.length} DOIs starting with _id #{cursor + 1}."
+        cursor = response.results.to_a.last[:sort].first.to_i
+
+        response.results.results.each do |d|
+          DeleteJob.perform_later(d.doi)
+        end
+      end
+    end
+
+    response.results.total
   end
 
   # register DOIs in the handle system that have not been registered yet
@@ -970,7 +996,7 @@ def self.transfer(options={})
     query = options[:query] || "*"
     size = (options[:size] || 1000).to_i
 
-    response = Doi.query(query, client_id: options[:client_id], page: { size: 1, cursor: 0 })
+    response = Doi.query(nil, client_id: options[:client_id], page: { size: 1, cursor: 0 })
     logger.info "[Transfer] #{response.results.total} DOIs found for client #{options[:client_id]}."
 
     if options[:client_id] && options[:target_id] && response.results.total > 0
@@ -978,7 +1004,7 @@ def self.transfer(options={})
       cursor = 0
 
       while response.results.results.length > 0 do
-        response = Doi.query(query, client_id: options[:client_id], page: { size: size, cursor: cursor })
+        response = Doi.query(nil, client_id: options[:client_id], page: { size: size, cursor: cursor })
         break unless response.results.results.length > 0
 
         logger.info "[Transfer] Transferring #{response.results.results.length} DOIs starting with _id #{cursor + 1}."
@@ -1024,7 +1050,7 @@ def self.migrate_landing_page(options={})
           "download-latency" => "downloadLatency"
         }
         result = result.map {|k, v| [mappings[k] || k, v] }.to_h
-#        doi.update_columns("last_landing_page_status_result": result)
+        # doi.update_columns("last_landing_page_status_result": result)
 
         # Do a fix of the stored download Latency
         # Sometimes was floating point precision, we dont need this
diff --git a/lib/tasks/client.rake b/lib/tasks/client.rake
index bd714095c..cea9387ae 100644
--- a/lib/tasks/client.rake
+++ b/lib/tasks/client.rake
@@ -91,28 +91,12 @@ namespace :client do
 
     # delete all associated prefixes and DOIs
     prefixes = client.prefixes.where.not('prefix IN (?)', prefixes_to_keep).pluck(:prefix)
-    prefix_ids = client.prefixes.where.not('prefix IN (?)', prefixes_to_keep).pluck(:id)
-
-    response = client.client_prefixes.destroy_all
-    puts "#{response.count} client prefixes deleted."
-
-    if prefix_ids.present?
-      response = ProviderPrefix.where('prefixes IN (?)', prefix_ids).destroy_all
-      puts "#{response.count} provider prefixes deleted."
-    end
-
-    if prefixes.present?
-      response = Prefix.where('prefix IN (?)', prefixes).destroy_all
-      puts "Prefixes #{prefixes.join(" and ")} deleted."
+    prefixes.each do |prefix|
+      ENV['PREFIX'] = prefix
+      Rake::Task["prefix:delete"].reenable
+      Rake::Task["prefix:delete"].invoke
     end
 
-    # delete DOIs in batches
-    puts "#{client.dois.length} DOIs will be deleted."
-    client.dois.find_each do |doi|
-      doi.destroy
-      puts "DOI #{doi.doi} deleted."
-    end
-    
     if client.update_attributes(is_active: nil, deleted_at: Time.zone.now)
       client.send_delete_email unless Rails.env.test?
       puts "Client with client ID #{ENV['CLIENT_ID']} deleted."
diff --git a/lib/tasks/doi.rake b/lib/tasks/doi.rake
index 5558539c2..25d71b6b8 100644
--- a/lib/tasks/doi.rake
+++ b/lib/tasks/doi.rake
@@ -129,12 +129,6 @@ namespace :doi do
     Doi.delete_test_dois(from_date: from_date)
   end
 
-  desc 'Delete DOIs with by prefix'
-  task :delete_test_dois => :environment do
-    prefix = ENV['PREFIX_TO_DELETE'] 
-    Doi.delete_dois_by_prefix(prefix) if prefix.present?
-  end
-
   desc 'Migrates landing page data handling camelCase changes at same time'
   task :migrate_landing_page => :environment do
     Doi.migrate_landing_page
diff --git a/lib/tasks/prefix.rake b/lib/tasks/prefix.rake
new file mode 100644
index 000000000..6164a372e
--- /dev/null
+++ b/lib/tasks/prefix.rake
@@ -0,0 +1,36 @@
+namespace :prefix do
+  desc 'Delete prefix and associated DOIs'
+  task :delete => :environment do
+    # These prefixes are used by multiple clients and can't be deleted
+    prefixes_to_keep = %w(10.5072 10.4124 10.4225 10.4226 10.4227)
+
+    if ENV['PREFIX'].nil?
+      puts "ENV['PREFIX'] is required."
+      exit
+    end
+
+    if prefixes_to_keep.include?(ENV['PREFIX'])
+      puts "Prefix #{ENV['PREFIX']} can't be deleted."
+      exit
+    end
+
+    prefix = Prefix.where(prefix: ENV['PREFIX']).first
+    if prefix.nil?
+      puts "Prefix #{ENV['PREFIX']} not found."
+      exit
+    end
+
+    ClientPrefix.where('prefixes = ?', prefix.id).destroy_all
+    puts "Client prefix deleted."
+
+    ProviderPrefix.where('prefixes = ?', prefix.id).destroy_all
+    puts "Provider prefix deleted."
+
+    prefix.destroy
+    puts "Prefix #{ENV['PREFIX']} deleted."
+
+    # delete DOIs
+    count = Doi.delete_dois_by_prefix(ENV['PREFIX'])
+    puts "#{count} DOIs with prefix #{ENV['PREFIX']} deleted."
+  end
+end