diff --git a/app/controllers/idv/gpo_controller.rb b/app/controllers/idv/gpo_controller.rb
index 80fb418888b..4ec812ed5dc 100644
--- a/app/controllers/idv/gpo_controller.rb
+++ b/app/controllers/idv/gpo_controller.rb
@@ -222,6 +222,8 @@ def enqueue_job
         document_capture_session,
         should_proof_state_id: false,
         trace_id: amzn_trace_id,
+        user_id: current_user.id,
+        threatmetrix_session_id: nil,
       )
     end
 
diff --git a/app/jobs/resolution_proofing_job.rb b/app/jobs/resolution_proofing_job.rb
index bac62cde043..e4c12850d44 100644
--- a/app/jobs/resolution_proofing_job.rb
+++ b/app/jobs/resolution_proofing_job.rb
@@ -13,7 +13,7 @@ class ResolutionProofingJob < ApplicationJob
   )
 
   def perform(result_id:, encrypted_arguments:, trace_id:, should_proof_state_id:,
-              dob_year_only:)
+              dob_year_only:, user_id: nil, threatmetrix_session_id: nil)
     timer = JobHelpers::Timer.new
 
     raise_stale_job! if stale_job?(enqueued_at)
@@ -25,6 +25,15 @@ def perform(result_id:, encrypted_arguments:, trace_id:, should_proof_state_id:,
 
     applicant_pii = decrypted_args[:applicant_pii]
 
+    threatmetrix_result = nil
+    if use_lexisnexis_ddp_threatmetrix_before_rdp_instant_verify?
+      user = User.find_by(id: user_id)
+      threatmetrix_result = proof_lexisnexis_ddp_with_threatmetrix(
+        applicant_pii, user, threatmetrix_session_id
+      )
+      log_threatmetrix_info(threatmetrix_result, user)
+    end
+
     callback_log_data = if dob_year_only && should_proof_state_id
                           proof_aamva_then_lexisnexis_dob_only(
                             timer: timer,
@@ -39,22 +48,48 @@ def perform(result_id:, encrypted_arguments:, trace_id:, should_proof_state_id:,
                           )
                         end
 
+    add_threatmetrix_result_to_callback_result(callback_log_data.result, threatmetrix_result)
+
     document_capture_session = DocumentCaptureSession.new(result_id: result_id)
     document_capture_session.store_proofing_result(callback_log_data.result)
   ensure
-    logger.info(
-      {
-        name: 'ProofResolution',
-        trace_id: trace_id,
-        resolution_success: callback_log_data&.resolution_success,
-        state_id_success: callback_log_data&.state_id_success,
-        timing: timer.results,
-      }.to_json,
+    logger_info_hash(
+      name: 'ProofResolution',
+      trace_id: trace_id,
+      resolution_success: callback_log_data&.resolution_success,
+      state_id_success: callback_log_data&.state_id_success,
+      timing: timer.results,
     )
   end
 
   private
 
+  def log_threatmetrix_info(threatmetrix_result, user)
+    logger_info_hash(
+      name: 'ThreatMetrix',
+      user_id: user&.uuid,
+      threatmetrix_request_id: threatmetrix_result.transaction_id,
+      threatmetrix_success: threatmetrix_result.success?,
+    )
+  end
+
+  def logger_info_hash(hash)
+    logger.info(hash.to_json)
+  end
+
+  def add_threatmetrix_result_to_callback_result(callback_log_data_result, threatmetrix_result)
+    callback_log_data_result[:threatmetrix_success] = threatmetrix_result.success?
+    callback_log_data_result[:threatmetrix_request_id] = threatmetrix_result.transaction_id
+  end
+
+  def proof_lexisnexis_ddp_with_threatmetrix(applicant_pii, user, threatmetrix_session_id)
+    return unless applicant_pii
+    ddp_pii = applicant_pii.dup
+    ddp_pii[:threatmetrix_session_id] = threatmetrix_session_id
+    ddp_pii[:email] = user&.confirmed_email_addresses&.first&.email
+    lexisnexis_ddp_proofer.proof(ddp_pii)
+  end
+
   # @return [CallbackLogData]
   def proof_lexisnexis_then_aamva(timer:, applicant_pii:, should_proof_state_id:)
     proofer_result = timer.time('resolution') do
@@ -202,6 +237,19 @@ def resolution_proofer
       end
   end
 
+  def lexisnexis_ddp_proofer
+    @lexisnexis_ddp_proofer ||=
+      if IdentityConfig.store.proofer_mock_fallback
+        Proofing::Mock::DdpMockClient.new
+      else
+        Proofing::LexisNexis::Ddp::Proofer.new(
+          api_key: IdentityConfig.store.lexisnexis_threatmetrix_api_key,
+          org_id: IdentityConfig.store.lexisnexis_threatmetrix_org_id,
+          base_url: IdentityConfig.store.lexisnexis_threatmetrix_base_url,
+        )
+      end
+  end
+
   def state_id_proofer
     @state_id_proofer ||=
       if IdentityConfig.store.proofer_mock_fallback
@@ -218,4 +266,8 @@ def state_id_proofer
         )
       end
   end
+
+  def use_lexisnexis_ddp_threatmetrix_before_rdp_instant_verify?
+    IdentityConfig.store.lexisnexis_threatmetrix_enabled
+  end
 end
diff --git a/app/services/idv/agent.rb b/app/services/idv/agent.rb
index 40a52232c96..47c3dc06b9a 100644
--- a/app/services/idv/agent.rb
+++ b/app/services/idv/agent.rb
@@ -5,7 +5,11 @@ def initialize(applicant)
     end
 
     def proof_resolution(
-      document_capture_session, should_proof_state_id:, trace_id:
+      document_capture_session,
+      should_proof_state_id:,
+      trace_id:,
+      user_id:,
+      threatmetrix_session_id:
     )
       document_capture_session.create_proofing_session
 
@@ -19,6 +23,8 @@ def proof_resolution(
         dob_year_only: IdentityConfig.store.proofing_send_partial_dob,
         trace_id: trace_id,
         result_id: document_capture_session.result_id,
+        user_id: user_id,
+        threatmetrix_session_id: threatmetrix_session_id,
       }
 
       if IdentityConfig.store.ruby_workers_idv_enabled
diff --git a/app/services/idv/steps/verify_base_step.rb b/app/services/idv/steps/verify_base_step.rb
index 5439ffe1597..d77af214924 100644
--- a/app/services/idv/steps/verify_base_step.rb
+++ b/app/services/idv/steps/verify_base_step.rb
@@ -49,6 +49,8 @@ def add_proofing_costs(results)
           if stage == :resolution
             # transaction_id comes from ConversationId
             add_cost(:lexis_nexis_resolution, transaction_id: hash[:transaction_id])
+            tmx_id = hash[:threatmetrix_request_id]
+            add_cost(:threatmetrix, transaction_id: tmx_id) if tmx_id
           elsif stage == :state_id
             process_aamva(hash[:transaction_id])
           end
@@ -176,6 +178,8 @@ def enqueue_job
           document_capture_session,
           should_proof_state_id: should_use_aamva?(pii),
           trace_id: amzn_trace_id,
+          user_id: user_id,
+          threatmetrix_session_id: flow_session[:threatmetrix_session_id],
         )
       end
 
diff --git a/app/services/proofing/lexis_nexis/ddp/proofer.rb b/app/services/proofing/lexis_nexis/ddp/proofer.rb
new file mode 100644
index 00000000000..f3f31230127
--- /dev/null
+++ b/app/services/proofing/lexis_nexis/ddp/proofer.rb
@@ -0,0 +1,49 @@
+module Proofing
+  module LexisNexis
+    module Ddp
+      class Proofer < LexisNexis::Proofer
+        vendor_name 'lexisnexis:ddp'
+
+        required_attributes :state_id_number,
+                            :threatmetrix_session_id,
+                            :state_id_number,
+                            :first_name,
+                            :last_name,
+                            :dob,
+                            :ssn,
+                            :address1,
+                            :city,
+                            :state,
+                            :zipcode
+
+        optional_attributes :address2, :phone, :email
+
+        stage :resolution
+
+        proof do |applicant, result|
+          proof_applicant(applicant, result)
+        end
+
+        def send_verification_request(applicant)
+          VerificationRequest.new(config: config, applicant: applicant).send
+        end
+
+        def proof_applicant(applicant, result)
+          response = send_verification_request(applicant)
+          process_response(response, result)
+        end
+
+        private
+
+        def process_response(response, result)
+          body = response.response_body
+          result.transaction_id = body['request_id']
+          request_result = body['request_result']
+          review_status = body['review_status']
+          result.add_error(:request_result, request_result) unless request_result == 'success'
+          result.add_error(:review_status, review_status) unless review_status == 'pass'
+        end
+      end
+    end
+  end
+end
diff --git a/app/services/proofing/lexis_nexis/ddp/verification_request.rb b/app/services/proofing/lexis_nexis/ddp/verification_request.rb
new file mode 100644
index 00000000000..2b895b87311
--- /dev/null
+++ b/app/services/proofing/lexis_nexis/ddp/verification_request.rb
@@ -0,0 +1,46 @@
+module Proofing
+  module LexisNexis
+    module Ddp
+      class VerificationRequest < Request
+        private
+
+        def build_request_body
+          {
+            api_key: config.api_key,
+            org_id: config.org_id,
+            account_address_street1: applicant[:address1],
+            account_address_street2: applicant[:address2] || '',
+            account_address_city: applicant[:city],
+            account_address_state: applicant[:state],
+            account_address_country: 'US',
+            account_address_zip: applicant[:zipcode],
+            account_date_of_birth: applicant[:dob] ?
+              Date.parse(applicant[:dob]).strftime('%Y%m%d') : '',
+            account_email: applicant[:email],
+            account_first_name: applicant[:first_name],
+            account_last_name: applicant[:last_name],
+            account_telephone: '', # applicant[:phone], decision was made not to send phone
+            drivers_license_number_hash: applicant[:state_id_number] ?
+              OpenSSL::Digest::SHA256.hexdigest(applicant[:state_id_number].gsub(/\W/, '')) : '',
+            event_type: 'ACCOUNT_CREATION',
+            service_type: 'all',
+            session_id: applicant[:threatmetrix_session_id],
+            ssn_hash: OpenSSL::Digest::SHA256.hexdigest(applicant[:ssn].gsub(/\D/, '')),
+          }.to_json
+        end
+
+        def metric_name
+          'lexis_nexis_ddp'
+        end
+
+        def url_request_path
+          '/api/session-query'
+        end
+
+        def timeout
+          IdentityConfig.store.lexisnexis_threatmetrix_timeout
+        end
+      end
+    end
+  end
+end
diff --git a/app/services/proofing/lexis_nexis/proofer.rb b/app/services/proofing/lexis_nexis/proofer.rb
index 967610ff24c..07cba134baa 100644
--- a/app/services/proofing/lexis_nexis/proofer.rb
+++ b/app/services/proofing/lexis_nexis/proofer.rb
@@ -12,6 +12,8 @@ class Proofer < Proofing::Base
         :password,
         :request_mode,
         :request_timeout,
+        :org_id,
+        :api_key,
         keyword_init: true,
         allowed_members: [
           :instant_verify_workflow,
diff --git a/app/services/proofing/mock/ddp_mock_client.rb b/app/services/proofing/mock/ddp_mock_client.rb
new file mode 100644
index 00000000000..acf18b3d8e2
--- /dev/null
+++ b/app/services/proofing/mock/ddp_mock_client.rb
@@ -0,0 +1,28 @@
+module Proofing
+  module Mock
+    class DdpMockClient < Proofing::Base
+      vendor_name 'DdpMock'
+
+      required_attributes :threatmetrix_session_id,
+                          :state_id_number,
+                          :first_name,
+                          :last_name,
+                          :dob,
+                          :ssn,
+                          :address1,
+                          :city,
+                          :state,
+                          :zipcode
+
+      optional_attributes :address2, :phone, :email
+
+      stage :resolution
+
+      TRANSACTION_ID = 'ddp-mock-transaction-id-123'
+
+      proof do |applicant, result|
+        result.transaction_id = TRANSACTION_ID
+      end
+    end
+  end
+end
diff --git a/config/application.yml.default b/config/application.yml.default
index 9d5fadab496..670c352a38f 100644
--- a/config/application.yml.default
+++ b/config/application.yml.default
@@ -139,14 +139,12 @@ lexisnexis_trueid_liveness_nocropping_workflow: customers.gsa.trueid.workflow
 lexisnexis_trueid_noliveness_cropping_workflow: customers.gsa.trueid.workflow
 lexisnexis_trueid_noliveness_nocropping_workflow: customers.gsa.trueid.workflow
 ###################################################################
-# LexisNexis ThreatMetrix ##########################################
+# LexisNexis DDP/ThreatMetrix #####################################
+lexisnexis_threatmetrix_api_key: test_api_key
 lexisnexis_threatmetrix_base_url: https://www.example.com
-lexisnexis_threatmetrix_request_mode: testing
 lexisnexis_threatmetrix_org_id: test_account
-lexisnexis_threatmetrix_username: test_username
-lexisnexis_threatmetrix_password: test_password
-lexisnexis_threatmetrix_instant_verify_timeout: 1.0
-lexisnexis_threatmetrix_instant_verify_workflow: customers.gsa.instant.verify.workflow
+lexisnexis_threatmetrix_timeout: 1.0
+lexisnexis_threatmetrix_enabled: false
 ###################################################################
 lockout_period_in_minutes: 10
 log_to_stdout: false
diff --git a/lib/identity_config.rb b/lib/identity_config.rb
index 17d9b9c0506..e9439310dcc 100644
--- a/lib/identity_config.rb
+++ b/lib/identity_config.rb
@@ -208,13 +208,11 @@ def self.build_store(config_map)
     config.add(:lexisnexis_trueid_noliveness_cropping_workflow, type: :string)
     config.add(:lexisnexis_trueid_noliveness_nocropping_workflow, type: :string)
     config.add(:lexisnexis_trueid_timeout, type: :float)
+    config.add(:lexisnexis_threatmetrix_api_key, type: :string)
     config.add(:lexisnexis_threatmetrix_base_url, type: :string)
-    config.add(:lexisnexis_threatmetrix_request_mode, type: :string)
+    config.add(:lexisnexis_threatmetrix_enabled, type: :string)
     config.add(:lexisnexis_threatmetrix_org_id, type: :string)
-    config.add(:lexisnexis_threatmetrix_username, type: :string)
-    config.add(:lexisnexis_threatmetrix_password, type: :string)
-    config.add(:lexisnexis_threatmetrix_instant_verify_timeout, type: :float)
-    config.add(:lexisnexis_threatmetrix_instant_verify_workflow, type: :string)
+    config.add(:lexisnexis_threatmetrix_timeout, type: :float)
     config.add(:liveness_checking_enabled, type: :boolean)
     config.add(:lockout_period_in_minutes, type: :integer)
     config.add(:log_to_stdout, type: :boolean)
diff --git a/spec/features/idv/doc_auth/verify_step_spec.rb b/spec/features/idv/doc_auth/verify_step_spec.rb
index 70d510d63cb..62e6d2a3056 100644
--- a/spec/features/idv/doc_auth/verify_step_spec.rb
+++ b/spec/features/idv/doc_auth/verify_step_spec.rb
@@ -157,16 +157,18 @@
       allow(IdentityConfig.store).to receive(:aamva_supported_jurisdictions).and_return(
         [Idp::Constants::MOCK_IDV_APPLICANT[:state_id_jurisdiction]],
       )
+      user = create(:user, :signed_up)
       expect_any_instance_of(Idv::Agent).
         to receive(:proof_resolution).
         with(
           anything,
           should_proof_state_id: true,
           trace_id: anything,
+          threatmetrix_session_id: nil,
+          user_id: user.id,
         ).
         and_call_original
 
-      user = create(:user, :signed_up)
       sign_in_and_2fa_user(user)
       complete_doc_auth_steps_before_verify_step
       click_idv_continue
@@ -181,16 +183,18 @@
         IdentityConfig.store.aamva_supported_jurisdictions -
           [Idp::Constants::MOCK_IDV_APPLICANT[:state_id_jurisdiction]],
       )
+      user = create(:user, :signed_up)
       expect_any_instance_of(Idv::Agent).
         to receive(:proof_resolution).
         with(
           anything,
           should_proof_state_id: false,
           trace_id: anything,
+          threatmetrix_session_id: nil,
+          user_id: user.id,
         ).
         and_call_original
 
-      user = create(:user, :signed_up)
       sign_in_and_2fa_user(user)
       complete_doc_auth_steps_before_verify_step
       click_idv_continue
@@ -203,17 +207,19 @@
     it 'does not perform the state ID check' do
       allow(IdentityConfig.store).to receive(:aamva_sp_banlist_issuers).
         and_return('["urn:gov:gsa:openidconnect:sp:server"]')
+      user = create(:user, :signed_up)
       expect_any_instance_of(Idv::Agent).
         to receive(:proof_resolution).
         with(
           anything,
           should_proof_state_id: false,
           trace_id: anything,
+          threatmetrix_session_id: nil,
+          user_id: user.id,
         ).
         and_call_original
 
       visit_idp_from_sp_with_ial1(:oidc)
-      user = create(:user, :signed_up)
       sign_in_and_2fa_user(user)
       complete_doc_auth_steps_before_verify_step
       click_idv_continue
diff --git a/spec/fixtures/proofing/lexis_nexis/ddp/error_response.json b/spec/fixtures/proofing/lexis_nexis/ddp/error_response.json
new file mode 100644
index 00000000000..4aa2c84f848
--- /dev/null
+++ b/spec/fixtures/proofing/lexis_nexis/ddp/error_response.json
@@ -0,0 +1,5 @@
+{
+  "error_detail": "service_type",
+  "request_id":"1234-abcd",
+  "request_result":"fail_invalid_parameter"
+}
diff --git a/spec/fixtures/proofing/lexis_nexis/ddp/request.json b/spec/fixtures/proofing/lexis_nexis/ddp/request.json
new file mode 100644
index 00000000000..bf7aefc8db4
--- /dev/null
+++ b/spec/fixtures/proofing/lexis_nexis/ddp/request.json
@@ -0,0 +1,20 @@
+{
+  "api_key": "test_api_key",
+  "org_id": "test_org_id",
+  "account_address_street1": "123 Main St",
+  "account_address_street2": "Ste 3",
+  "account_address_city": "Baton Rouge",
+  "account_address_state": "LA",
+  "account_address_country": "US",
+  "account_address_zip": "70802-12345",
+  "account_date_of_birth": "19800101",
+  "account_email": "test@example.com",
+  "account_first_name": "Testy",
+  "account_last_name": "McTesterson",
+  "account_telephone": "",
+  "drivers_license_number_hash": "ef797c8118f02dfb649607dd5d3f8c7623048c9c063d532cc95c5ed7a898a64f",
+  "event_type": "ACCOUNT_CREATION",
+  "service_type": "all",
+  "session_id": "UNIQUE_SESSION_ID",
+  "ssn_hash": "15e2b0d3c33891ebb0f1ef609ec419420c20e320ce94c65fbc8c3312448eb225"
+}
diff --git a/spec/fixtures/proofing/lexis_nexis/ddp/successful_response.json b/spec/fixtures/proofing/lexis_nexis/ddp/successful_response.json
new file mode 100644
index 00000000000..1d95511b371
--- /dev/null
+++ b/spec/fixtures/proofing/lexis_nexis/ddp/successful_response.json
@@ -0,0 +1,18 @@
+{
+  "account_address_result": "success",
+  "account_address_score": "0",
+  "account_email_result": "success",
+  "account_email_score": "0",
+  "account_name_result": "success",
+  "account_name_score": "0",
+  "account_telephone_result": "success",
+  "account_telephone_score": "0",
+  "request_id": "1234",
+  "request_result": "success",
+  "review_status": "pass",
+  "risk_rating": "trusted",
+  "ssn_hash_result": "success",
+  "ssn_hash_score": "0",
+  "summary_risk_score": "-6",
+  "tmx_risk_rating": "neutral"
+}
diff --git a/spec/jobs/resolution_proofing_job_spec.rb b/spec/jobs/resolution_proofing_job_spec.rb
index 0980635a298..dfd4328d936 100644
--- a/spec/jobs/resolution_proofing_job_spec.rb
+++ b/spec/jobs/resolution_proofing_job_spec.rb
@@ -39,6 +39,9 @@
     instance_double(Proofing::Aamva::Proofer, class: Proofing::Aamva::Proofer)
   end
   let(:trace_id) { SecureRandom.uuid }
+  let(:user) { build(:user, :signed_up) }
+  let(:threatmetrix_session_id) { SecureRandom.uuid }
+  let(:threatmetrix_request_id) { '1234' }
 
   describe '.perform_later' do
     it 'stores results' do
@@ -48,6 +51,8 @@
         dob_year_only: dob_year_only,
         encrypted_arguments: encrypted_arguments,
         trace_id: trace_id,
+        user_id: user.id,
+        threatmetrix_session_id: threatmetrix_session_id,
       )
 
       result = document_capture_session.load_proofing_result[:result]
@@ -65,17 +70,25 @@
         dob_year_only: dob_year_only,
         encrypted_arguments: encrypted_arguments,
         trace_id: trace_id,
+        user_id: user.id,
+        threatmetrix_session_id: threatmetrix_session_id,
       )
     end
 
-    context 'webmock lexisnexis' do
+    context 'webmock lexisnexis and threatmetrix' do
       before do
         stub_request(
           :post,
           'https://lexisnexis.example.com/restws/identity/v2/abc123/aaa/conversation',
         ).to_return(body: lexisnexis_response.to_json)
+        stub_request(
+          :post,
+          'https://www.example.com/api/session-query',
+        ).to_return(body: LexisNexisFixtures.ddp_success_response_json)
 
         allow(IdentityConfig.store).to receive(:proofer_mock_fallback).and_return(false)
+        allow(IdentityConfig.store).to receive(:lexisnexis_threatmetrix_enabled).
+          and_return(true)
 
         allow(IdentityConfig.store).to receive(:lexisnexis_account_id).and_return('abc123')
         allow(IdentityConfig.store).to receive(:lexisnexis_request_mode).and_return('aaa')
@@ -140,6 +153,8 @@
           },
           transaction_id: lexisnexis_transaction_id,
           reference: lexisnexis_reference,
+          threatmetrix_success: true,
+          threatmetrix_request_id: threatmetrix_request_id,
         )
       end
 
@@ -216,6 +231,8 @@
             },
             transaction_id: lexisnexis_transaction_id,
             reference: lexisnexis_reference,
+            threatmetrix_request_id: threatmetrix_request_id,
+            threatmetrix_success: true,
           )
         end
       end
@@ -235,13 +252,23 @@
             and_return(Proofing::Result.new)
         end
 
-        it 'logs the trace_id and timing info' do
-          expect(instance.logger).to receive(:info) do |message|
-            expect(JSON.parse(message, symbolize_names: true)).to include(
+        it 'logs the trace_id and timing info for ProofResolution and the Threatmetrix info' do
+          expect(instance).to receive(:logger_info_hash).ordered.with(
+            hash_including(
+              name: 'ThreatMetrix',
+              user_id: nil,
+              threatmetrix_request_id: Proofing::Mock::DdpMockClient::TRANSACTION_ID,
+              threatmetrix_success: true,
+            ),
+          )
+
+          expect(instance).to receive(:logger_info_hash).ordered.with(
+            hash_including(
               :timing,
+              name: 'ProofResolution',
               trace_id: trace_id,
-            )
-          end
+            ),
+          )
 
           perform
         end
diff --git a/spec/services/idv/agent_spec.rb b/spec/services/idv/agent_spec.rb
index 2b941f7767e..3f11d6e6463 100644
--- a/spec/services/idv/agent_spec.rb
+++ b/spec/services/idv/agent_spec.rb
@@ -25,7 +25,11 @@
             Idp::Constants::MOCK_IDV_APPLICANT.merge(uuid: user.uuid, ssn: '444-55-6666'),
           )
           agent.proof_resolution(
-            document_capture_session, should_proof_state_id: true, trace_id: trace_id
+            document_capture_session,
+            should_proof_state_id: true,
+            trace_id: trace_id,
+            user_id: user.id,
+            threatmetrix_session_id: nil,
           )
 
           result = document_capture_session.load_proofing_result.result
@@ -36,7 +40,11 @@
         it 'does proof state_id if resolution succeeds' do
           agent = Idv::Agent.new(Idp::Constants::MOCK_IDV_APPLICANT_WITH_SSN.merge(uuid: user.uuid))
           agent.proof_resolution(
-            document_capture_session, should_proof_state_id: true, trace_id: trace_id
+            document_capture_session,
+            should_proof_state_id: true,
+            trace_id: trace_id,
+            user_id: user.id,
+            threatmetrix_session_id: nil,
           )
           result = document_capture_session.load_proofing_result.result
           expect(result[:context][:stages][:state_id]).to include(
@@ -52,7 +60,11 @@
             Idp::Constants::MOCK_IDV_APPLICANT.merge(uuid: user.uuid, ssn: '444-55-6666'),
           )
           agent.proof_resolution(
-            document_capture_session, should_proof_state_id: true, trace_id: trace_id
+            document_capture_session,
+            should_proof_state_id: true,
+            trace_id: trace_id,
+            user_id: user.id,
+            threatmetrix_session_id: nil,
           )
           result = document_capture_session.load_proofing_result.result
           expect(result[:errors][:ssn]).to eq ['Unverified SSN.']
@@ -62,7 +74,11 @@
         it 'does not proof state_id if resolution succeeds' do
           agent = Idv::Agent.new(Idp::Constants::MOCK_IDV_APPLICANT_WITH_SSN.merge(uuid: user.uuid))
           agent.proof_resolution(
-            document_capture_session, should_proof_state_id: false, trace_id: trace_id
+            document_capture_session,
+            should_proof_state_id: false,
+            trace_id: trace_id,
+            user_id: user.id,
+            threatmetrix_session_id: nil,
           )
 
           result = document_capture_session.load_proofing_result.result
@@ -78,7 +94,11 @@
           )
 
           agent.proof_resolution(
-            document_capture_session, should_proof_state_id: false, trace_id: trace_id
+            document_capture_session,
+            should_proof_state_id: false,
+            trace_id: trace_id,
+            user_id: user.id,
+            threatmetrix_session_id: nil,
           )
           result = document_capture_session.load_proofing_result.result
 
@@ -97,7 +117,11 @@
         )
 
         agent.proof_resolution(
-          document_capture_session, should_proof_state_id: true, trace_id: trace_id
+          document_capture_session,
+          should_proof_state_id: true,
+          trace_id: trace_id,
+          user_id: user.id,
+          threatmetrix_session_id: nil,
         )
         result = document_capture_session.load_proofing_result.result
 
@@ -117,7 +141,10 @@
       it 'proofs addresses successfully with valid information' do
         agent = Idv::Agent.new({ phone: Faker::PhoneNumber.cell_phone })
         agent.proof_address(
-          document_capture_session, trace_id: trace_id, user_id: user_id, issuer: issuer
+          document_capture_session,
+          trace_id: trace_id,
+          user_id: user_id,
+          issuer: issuer,
         )
         result = document_capture_session.load_proofing_result[:result]
         expect(result[:context][:stages]).to include({ address: 'AddressMock' })
diff --git a/spec/services/idv/steps/ipp/verify_step_spec.rb b/spec/services/idv/steps/ipp/verify_step_spec.rb
index 0987bc9c936..0cba80606e0 100644
--- a/spec/services/idv/steps/ipp/verify_step_spec.rb
+++ b/spec/services/idv/steps/ipp/verify_step_spec.rb
@@ -52,6 +52,8 @@
           kind_of(DocumentCaptureSession),
           should_proof_state_id: anything,
           trace_id: amzn_trace_id,
+          threatmetrix_session_id: nil,
+          user_id: anything,
         )
 
       step.call
diff --git a/spec/services/idv/steps/verify_step_spec.rb b/spec/services/idv/steps/verify_step_spec.rb
index 832e317307b..79ff6ed8616 100644
--- a/spec/services/idv/steps/verify_step_spec.rb
+++ b/spec/services/idv/steps/verify_step_spec.rb
@@ -60,6 +60,8 @@
           kind_of(DocumentCaptureSession),
           should_proof_state_id: anything,
           trace_id: amzn_trace_id,
+          threatmetrix_session_id: nil,
+          user_id: user.id,
         )
 
       step.call
diff --git a/spec/services/proofing/lexis_nexis/ddp/proofing_spec.rb b/spec/services/proofing/lexis_nexis/ddp/proofing_spec.rb
new file mode 100644
index 00000000000..0b5e2588cf7
--- /dev/null
+++ b/spec/services/proofing/lexis_nexis/ddp/proofing_spec.rb
@@ -0,0 +1,74 @@
+require 'rails_helper'
+
+describe Proofing::LexisNexis::Ddp::Proofer do
+  let(:applicant) do
+    {
+      first_name: 'Testy',
+      last_name: 'McTesterson',
+      ssn: '123456789',
+      dob: '01/01/1980',
+      address1: '123 Main St',
+      address2: 'Ste 3',
+      city: 'Baton Rouge',
+      state: 'LA',
+      zipcode: '70802-12345',
+      state_id_number: '12345678',
+      threatmetrix_session_id: '123456',
+      phone: '5551231234',
+      email: 'test@example.com',
+    }
+  end
+  let(:verification_request) do
+    Proofing::LexisNexis::Ddp::VerificationRequest.new(
+      applicant: applicant,
+      config: LexisNexisFixtures.example_config,
+    )
+  end
+
+  describe '#send' do
+    context 'when the request times out' do
+      it 'raises a timeout error' do
+        stub_request(:post, verification_request.url).to_timeout
+
+        expect { verification_request.send }.to raise_error(
+          Proofing::TimeoutError,
+          'LexisNexis timed out waiting for verification response',
+        )
+      end
+    end
+
+    context 'when the request is made' do
+      it 'it looks like the right request' do
+        request = stub_request(:post, verification_request.url).
+          with(body: verification_request.body, headers: verification_request.headers).
+          to_return(body: LexisNexisFixtures.ddp_success_response_json, status: 200)
+
+        verification_request.send
+
+        expect(request).to have_been_requested.once
+      end
+    end
+  end
+
+  subject(:instance) do
+    Proofing::LexisNexis::Ddp::Proofer.new(**LexisNexisFixtures.example_config.to_h)
+  end
+
+  describe '#proof' do
+    subject(:result) { instance.proof(applicant) }
+
+    before do
+      stub_request(:post, verification_request.url).
+        to_return(body: response_body, status: 200)
+    end
+
+    context 'when the response is a full match' do
+      let(:response_body) { LexisNexisFixtures.ddp_success_response_json }
+
+      it 'is a successful result' do
+        expect(result.success?).to eq(true)
+        expect(result.errors).to be_empty
+      end
+    end
+  end
+end
diff --git a/spec/services/proofing/lexis_nexis/ddp/verification_request_spec.rb b/spec/services/proofing/lexis_nexis/ddp/verification_request_spec.rb
new file mode 100644
index 00000000000..ec7c7d71c91
--- /dev/null
+++ b/spec/services/proofing/lexis_nexis/ddp/verification_request_spec.rb
@@ -0,0 +1,52 @@
+require 'rails_helper'
+
+describe Proofing::LexisNexis::Ddp::VerificationRequest do
+  let(:dob) { '1980-01-01' }
+  let(:applicant) do
+    {
+      first_name: 'Testy',
+      last_name: 'McTesterson',
+      ssn: '123-45-6789',
+      dob: dob,
+      address1: '123 Main St',
+      address2: 'Ste 3',
+      city: 'Baton Rouge',
+      state: 'LA',
+      zipcode: '70802-12345',
+      state_id_number: '12345678',
+      threatmetrix_session_id: 'UNIQUE_SESSION_ID',
+      phone: '5551231234',
+      email: 'test@example.com',
+    }
+  end
+
+  let(:response_body) { LexisNexisFixtures.ddp_success_response_json }
+  subject do
+    described_class.new(applicant: applicant, config: LexisNexisFixtures.example_ddp_config)
+  end
+
+  describe '#body' do
+    it 'returns a properly formed request body' do
+      expect(subject.body).to eq(LexisNexisFixtures.ddp_request_json)
+    end
+
+    context 'without an address line 2' do
+      let(:applicant) do
+        hash = super()
+        hash.delete(:address2)
+        hash
+      end
+
+      it 'sets StreetAddress2 to and empty string' do
+        parsed_body = JSON.parse(subject.body, symbolize_names: true)
+        expect(parsed_body[:account_address_street2]).to eq('')
+      end
+    end
+  end
+
+  describe '#url' do
+    it 'returns a url for the DDP session query endpoint' do
+      expect(subject.url).to eq('https://example.com/api/session-query')
+    end
+  end
+end
diff --git a/spec/support/lexis_nexis_fixtures.rb b/spec/support/lexis_nexis_fixtures.rb
index f58c92a6055..ab1c91b78f4 100644
--- a/spec/support/lexis_nexis_fixtures.rb
+++ b/spec/support/lexis_nexis_fixtures.rb
@@ -14,6 +14,34 @@ def example_config
       )
     end
 
+    def example_ddp_config
+      Proofing::LexisNexis::Proofer::Config.new(
+        api_key: 'test_api_key',
+        base_url: 'https://example.com',
+        org_id: 'test_org_id',
+      )
+    end
+
+    def ddp_request_json
+      raw = read_fixture_file_at_path('ddp/request.json')
+      JSON.parse(raw).to_json
+    end
+
+    def ddp_success_response_json
+      raw = read_fixture_file_at_path('ddp/successful_response.json')
+      JSON.parse(raw).to_json
+    end
+
+    def ddp_failure_response_json
+      raw = read_fixture_file_at_path('ddp/failed_response.json')
+      JSON.parse(raw).to_json
+    end
+
+    def ddp_error_response_json
+      raw = read_fixture_file_at_path('ddp/error_response.json')
+      JSON.parse(raw).to_json
+    end
+
     def instant_verify_request_json
       raw = read_fixture_file_at_path('instant_verify/request.json')
       JSON.parse(raw).to_json