diff --git a/app/models/poll/voter.rb b/app/models/poll/voter.rb
index 66395aa67..2ea150718 100644
--- a/app/models/poll/voter.rb
+++ b/app/models/poll/voter.rb
@@ -14,7 +14,8 @@ class Poll
     validates :booth_assignment_id, presence: true, if: ->(voter) { voter.origin == "booth" }
     validates :officer_assignment_id, presence: true, if: ->(voter) { voter.origin == "booth" }
 
-    validates :document_number, presence: true, uniqueness: { scope: [:poll_id, :document_type], message: :has_voted }, unless: :skip_user_verification?
+    validates :document_number, presence: true, unless: :skip_user_verification?
+    validates :user_id, uniqueness: { scope: [:poll_id], message: :has_voted }
     validates :origin, inclusion: { in: VALID_ORIGINS }
 
     before_validation :set_demographic_info, :set_document_info, :set_denormalized_booth_assignment_id
diff --git a/config/locales/en/activerecord.yml b/config/locales/en/activerecord.yml
index 9ea6e1c51..dd024d838 100644
--- a/config/locales/en/activerecord.yml
+++ b/config/locales/en/activerecord.yml
@@ -508,6 +508,7 @@ en:
           attributes:
             document_number:
               not_in_census: "Document not in census"
+            user_id:
               has_voted: "User has already voted"
         legislation/process:
           attributes:
diff --git a/config/locales/es/activerecord.yml b/config/locales/es/activerecord.yml
index c3bc2c3e9..3d324a27c 100644
--- a/config/locales/es/activerecord.yml
+++ b/config/locales/es/activerecord.yml
@@ -510,6 +510,7 @@ es:
           attributes:
             document_number:
               not_in_census: "Este documento no aparece en el censo"
+            user_id:
               has_voted: "Este usuario ya ha votado"
         legislation/process:
           attributes:
diff --git a/spec/models/poll/voter_spec.rb b/spec/models/poll/voter_spec.rb
index c919e971f..9ed82be67 100644
--- a/spec/models/poll/voter_spec.rb
+++ b/spec/models/poll/voter_spec.rb
@@ -34,7 +34,7 @@ describe Poll::Voter do
       voter = build(:poll_voter, user: user, poll: poll)
 
       expect(voter).not_to be_valid
-      expect(voter.errors.messages[:document_number]).to eq(["User has already voted"])
+      expect(voter.errors.messages[:user_id]).to eq(["User has already voted"])
     end
 
     it "is not valid if the user has already voted in the same poll/booth" do
@@ -43,7 +43,7 @@ describe Poll::Voter do
       voter = build(:poll_voter, user: user, poll: poll, booth_assignment: booth_assignment)
 
       expect(voter).not_to be_valid
-      expect(voter.errors.messages[:document_number]).to eq(["User has already voted"])
+      expect(voter.errors.messages[:user_id]).to eq(["User has already voted"])
     end
 
     it "is not valid if the user has already voted in different booth in the same poll" do
@@ -52,7 +52,7 @@ describe Poll::Voter do
       voter = build(:poll_voter, :from_booth, user: user, poll: poll, booth: booth)
 
       expect(voter).not_to be_valid
-      expect(voter.errors.messages[:document_number]).to eq(["User has already voted"])
+      expect(voter.errors.messages[:user_id]).to eq(["User has already voted"])
     end
 
     it "is valid if the user has already voted in the same booth in different poll" do
@@ -69,7 +69,31 @@ describe Poll::Voter do
 
       voter = build(:poll_voter, poll: answer.question.poll, user: answer.author)
       expect(voter).not_to be_valid
-      expect(voter.errors.messages[:document_number]).to eq(["User has already voted"])
+      expect(voter.errors.messages[:user_id]).to eq(["User has already voted"])
+    end
+
+    context "Skip verification is enabled" do
+      before do
+        Setting["feature.user.skip_verification"] = true
+        user.update!(document_number: nil, document_type: nil)
+      end
+
+      it "is not valid if the user has already voted in the same poll" do
+        create(:poll_voter, user: user, poll: poll)
+
+        voter = build(:poll_voter, user: user, poll: poll)
+
+        expect(voter).not_to be_valid
+      end
+
+      it "is valid if other users have voted in the same poll" do
+        another_user = create(:user, :level_two, document_number: nil, document_type: nil)
+        create(:poll_voter, user: another_user, poll: poll)
+
+        voter = build(:poll_voter, user: user, poll: poll)
+
+        expect(voter).to be_valid
+      end
     end
 
     context "origin" do