diff --git a/src/main/java/org/prebid/server/bidder/vungle/VungleBidder.java b/src/main/java/org/prebid/server/bidder/vungle/VungleBidder.java
index f10a2dcc453..1f6788c800f 100644
--- a/src/main/java/org/prebid/server/bidder/vungle/VungleBidder.java
+++ b/src/main/java/org/prebid/server/bidder/vungle/VungleBidder.java
@@ -59,11 +59,16 @@ public Result<List<HttpRequest<BidRequest>>> makeHttpRequests(BidRequest bidRequ
         final List<BidderError> errors = new ArrayList<>();
         final List<HttpRequest<BidRequest>> httpRequests = new ArrayList<>();
 
+        final String buyerId = ObjectUtil.getIfNotNull(bidRequest.getUser(), User::getBuyeruid);
+        if (StringUtils.isBlank(buyerId)) {
+            return Result.withError(BidderError.badInput("missing bidder token in user.buyeruid"));
+        }
+
         for (Imp imp : bidRequest.getImp()) {
             try {
                 final Price price = resolveBidFloor(imp, bidRequest);
                 final VungleImpressionExt impExt = parseImpExt(imp);
-                final VungleImpressionExt modifiedImpExt = modifyImpExt(impExt, bidRequest);
+                final VungleImpressionExt modifiedImpExt = modifyImpExt(impExt, buyerId);
                 final Imp modifiedImp = modifyImp(imp, modifiedImpExt, price);
                 final BidRequest modifiedRequest = modifyBidRequest(
                         bidRequest,
@@ -95,9 +100,8 @@ private VungleImpressionExt parseImpExt(Imp imp) {
         return mapper.mapper().convertValue(imp.getExt(), VungleImpressionExt.class);
     }
 
-    private static VungleImpressionExt modifyImpExt(VungleImpressionExt impExt, BidRequest bidRequest) {
+    private static VungleImpressionExt modifyImpExt(VungleImpressionExt impExt, String buyerId) {
         final ExtImpVungle bidder = impExt.getBidder();
-        final String buyerId = ObjectUtil.getIfNotNull(bidRequest.getUser(), User::getBuyeruid);
         final ExtImpVungle vungle = ExtImpVungle.of(
                 buyerId,
                 bidder.getAppStoreId(),
diff --git a/src/test/java/org/prebid/server/bidder/vungle/VungleBidderTest.java b/src/test/java/org/prebid/server/bidder/vungle/VungleBidderTest.java
index 31967ae4523..5306ef7da2e 100644
--- a/src/test/java/org/prebid/server/bidder/vungle/VungleBidderTest.java
+++ b/src/test/java/org/prebid/server/bidder/vungle/VungleBidderTest.java
@@ -175,6 +175,54 @@ public void makeHttpRequestsShouldThrowErrorWhenCurrencyConvertCannotConvertInAn
                 .containsExactly("Unable to convert from currency UAH to desired ad server currency USD");
     }
 
+    @Test
+    public void makeHttpRequestsShouldReturnErrorWhenUserIsNull() {
+        // given
+        final BidRequest bidRequest = givenBidRequest(
+                bidRequestBuilder -> bidRequestBuilder.user(null), identity());
+
+        // when
+        final Result<List<HttpRequest<BidRequest>>> result = target.makeHttpRequests(bidRequest);
+
+        // then
+        assertThat(result.getValue()).isEmpty();
+        assertThat(result.getErrors())
+                .extracting(BidderError::getMessage)
+                .containsExactly("missing bidder token in user.buyeruid");
+    }
+
+    @Test
+    public void makeHttpRequestsShouldReturnErrorWhenUserBuyeruidIsNull() {
+        // given
+        final BidRequest bidRequest = givenBidRequest(
+                bidRequestBuilder -> bidRequestBuilder.user(User.builder().buyeruid(null).build()), identity());
+
+        // when
+        final Result<List<HttpRequest<BidRequest>>> result = target.makeHttpRequests(bidRequest);
+
+        // then
+        assertThat(result.getValue()).isEmpty();
+        assertThat(result.getErrors())
+                .extracting(BidderError::getMessage)
+                .containsExactly("missing bidder token in user.buyeruid");
+    }
+
+    @Test
+    public void makeHttpRequestsShouldReturnErrorWhenUserBuyeruidIsBlank() {
+        // given
+        final BidRequest bidRequest = givenBidRequest(
+                bidRequestBuilder -> bidRequestBuilder.user(User.builder().buyeruid(" ").build()), identity());
+
+        // when
+        final Result<List<HttpRequest<BidRequest>>> result = target.makeHttpRequests(bidRequest);
+
+        // then
+        assertThat(result.getValue()).isEmpty();
+        assertThat(result.getErrors())
+                .extracting(BidderError::getMessage)
+                .containsExactly("missing bidder token in user.buyeruid");
+    }
+
     @Test
     public void makeHttpRequestShouldUpdateExtImpVungleWhenUserBuyeruidPresent() {
         // given
@@ -380,12 +428,14 @@ public void makeBidsShouldReturnVideoBidIfBaneerIsPresentInRequestImp() throws J
                 .containsOnly(BidderBid.of(Bid.builder().impid("123").build(), video, "seat", null));
     }
 
+    @SafeVarargs
     private static BidRequest givenBidRequest(
             UnaryOperator<BidRequest.BidRequestBuilder> bidRequestCustomizer,
             UnaryOperator<Imp.ImpBuilder>... impCustomizer) {
 
         return bidRequestCustomizer.apply(BidRequest.builder()
                         .app(App.builder().build())
+                        .user(User.builder().buyeruid("buyeruid").build())
                         .imp(Arrays.stream(impCustomizer).map(VungleBidderTest::givenImp).toList()))
                 .build();
     }
diff --git a/src/test/resources/org/prebid/server/it/openrtb2/liftoff/test-auction-liftoff-request.json b/src/test/resources/org/prebid/server/it/openrtb2/liftoff/test-auction-liftoff-request.json
index a10f5c85f11..d80279a635d 100644
--- a/src/test/resources/org/prebid/server/it/openrtb2/liftoff/test-auction-liftoff-request.json
+++ b/src/test/resources/org/prebid/server/it/openrtb2/liftoff/test-auction-liftoff-request.json
@@ -12,13 +12,15 @@
       },
       "ext": {
         "liftoff": {
-          "bid_token": "bid_token",
           "app_store_id": "app_store_id",
           "placement_reference_id": "placement_reference_id"
         }
       }
     }
   ],
+  "user": {
+    "buyeruid": "bid_token"
+  },
   "tmax": 5000,
   "regs": {
     "ext": {
diff --git a/src/test/resources/org/prebid/server/it/openrtb2/liftoff/test-liftoff-bid-request.json b/src/test/resources/org/prebid/server/it/openrtb2/liftoff/test-liftoff-bid-request.json
index 9348868846c..ef277198b76 100644
--- a/src/test/resources/org/prebid/server/it/openrtb2/liftoff/test-liftoff-bid-request.json
+++ b/src/test/resources/org/prebid/server/it/openrtb2/liftoff/test-liftoff-bid-request.json
@@ -14,17 +14,20 @@
       },
       "ext": {
         "bidder": {
-          "bid_token": "bid_token",
           "app_store_id": "app_store_id",
           "placement_reference_id": "placement_reference_id"
         },
         "vungle": {
+          "bid_token": "bid_token",
           "app_store_id": "app_store_id",
           "placement_reference_id": "placement_reference_id"
         }
       }
     }
   ],
+  "user": {
+    "buyeruid": "bid_token"
+  },
   "source": {
     "tid": "${json-unit.any-string}"
   },
diff --git a/src/test/resources/org/prebid/server/it/openrtb2/vungle/test-auction-vungle-request.json b/src/test/resources/org/prebid/server/it/openrtb2/vungle/test-auction-vungle-request.json
index d4a33b89ed4..50010c7e41a 100644
--- a/src/test/resources/org/prebid/server/it/openrtb2/vungle/test-auction-vungle-request.json
+++ b/src/test/resources/org/prebid/server/it/openrtb2/vungle/test-auction-vungle-request.json
@@ -12,13 +12,15 @@
       },
       "ext": {
         "vungle": {
-          "bid_token": "bid_token",
           "app_store_id": "app_store_id",
           "placement_reference_id": "placement_reference_id"
         }
       }
     }
   ],
+  "user": {
+    "buyeruid": "bid_token"
+  },
   "tmax": 5000,
   "regs": {
     "ext": {
diff --git a/src/test/resources/org/prebid/server/it/openrtb2/vungle/test-vungle-bid-request.json b/src/test/resources/org/prebid/server/it/openrtb2/vungle/test-vungle-bid-request.json
index 9348868846c..ef277198b76 100644
--- a/src/test/resources/org/prebid/server/it/openrtb2/vungle/test-vungle-bid-request.json
+++ b/src/test/resources/org/prebid/server/it/openrtb2/vungle/test-vungle-bid-request.json
@@ -14,17 +14,20 @@
       },
       "ext": {
         "bidder": {
-          "bid_token": "bid_token",
           "app_store_id": "app_store_id",
           "placement_reference_id": "placement_reference_id"
         },
         "vungle": {
+          "bid_token": "bid_token",
           "app_store_id": "app_store_id",
           "placement_reference_id": "placement_reference_id"
         }
       }
     }
   ],
+  "user": {
+    "buyeruid": "bid_token"
+  },
   "source": {
     "tid": "${json-unit.any-string}"
   },