diff --git a/src/Elastic.Clients.Elasticsearch/_Shared/Core/Infer/IndexName/IndexNameResolver.cs b/src/Elastic.Clients.Elasticsearch/_Shared/Core/Infer/IndexName/IndexNameResolver.cs
index 82526235753..d71b6aa0ae5 100644
--- a/src/Elastic.Clients.Elasticsearch/_Shared/Core/Infer/IndexName/IndexNameResolver.cs
+++ b/src/Elastic.Clients.Elasticsearch/_Shared/Core/Infer/IndexName/IndexNameResolver.cs
@@ -28,6 +28,13 @@ public string Resolve(IndexName i)
 	}
 
 	public string Resolve(Type type)
+	{
+		var indexName = TryResolve(type);
+		ValidateIndexName(indexName);
+		return indexName;
+	}
+
+	public string? TryResolve(Type type)
 	{
 		var indexName = _transportClientSettings.DefaultIndex;
 		var defaultIndices = _transportClientSettings.DefaultIndices;
@@ -36,8 +43,8 @@ public string Resolve(Type type)
 			if (defaultIndices.TryGetValue(type, out var value) && !string.IsNullOrEmpty(value))
 				indexName = value;
 		}
-		ValidateIndexName(indexName);
-		return indexName;
+
+		return string.IsNullOrWhiteSpace(indexName) ? null : indexName;
 	}
 
 	private static string PrefixClusterName(IndexName i, string name) => i.Cluster.IsNullOrEmpty() ? name : $"{i.Cluster}:{name}";
diff --git a/src/Elastic.Clients.Elasticsearch/_Shared/Core/Infer/Inferrer.cs b/src/Elastic.Clients.Elasticsearch/_Shared/Core/Infer/Inferrer.cs
index 886ae41e0c9..f051df3e36b 100644
--- a/src/Elastic.Clients.Elasticsearch/_Shared/Core/Infer/Inferrer.cs
+++ b/src/Elastic.Clients.Elasticsearch/_Shared/Core/Infer/Inferrer.cs
@@ -41,6 +41,8 @@ public Inferrer(IElasticsearchClientSettings elasticsearchClientSettings)
 
 	public string IndexName(IndexName index) => IndexNameResolver.Resolve(index);
 
+	public string? TryIndexName(Type type) => IndexNameResolver.TryResolve(type);
+
 	public string? Id<[DynamicallyAccessedMembers(PublicProperties | NonPublicProperties)] T>(T instance) => IdResolver.Resolve(instance);
 
 	public string? Id([DynamicallyAccessedMembers(PublicProperties | NonPublicProperties)] Type type, object instance) => IdResolver.Resolve(type, instance);
diff --git a/src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkDeleteOperation.cs b/src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkDeleteOperation.cs
index 1ec0908821a..104d6408c4c 100644
--- a/src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkDeleteOperation.cs
+++ b/src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkDeleteOperation.cs
@@ -102,8 +102,6 @@ protected override void SetValues(IElasticsearchClientSettings settings)
 			if (!string.IsNullOrEmpty(routing.GetString(settings)))
 				Routing = routing;
 		}
-
-		Index ??= typeof(T);
 	}
 
 	protected override Type ClrType => typeof(T);
diff --git a/src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkDeleteOperationDescriptor.cs b/src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkDeleteOperationDescriptor.cs
index 909528f2887..03bee581c65 100644
--- a/src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkDeleteOperationDescriptor.cs
+++ b/src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkDeleteOperationDescriptor.cs
@@ -43,6 +43,5 @@ public BulkDeleteOperationDescriptor(TDocument documentToDelete) :
 		this(new Id(documentToDelete))
 	{
 		Instance.Routing = new Routing(documentToDelete);
-		Instance.Index = IndexName.From<TDocument>();
 	}
 }
diff --git a/src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkOperation.cs b/src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkOperation.cs
index 64176224271..8fedfa07aec 100644
--- a/src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkOperation.cs
+++ b/src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkOperation.cs
@@ -103,17 +103,49 @@ internal BulkOperation()
 	/// <param name="settings">The <see cref="IElasticsearchClientSettings"/> for the current client instance.</param>
 	protected abstract Task SerializeAsync(Stream stream, IElasticsearchClientSettings settings);
 
+	private IndexName? _bulkRequestIndex;
+
 	void IBulkOperation.PrepareIndex(IndexName? bulkRequestIndex)
 	{
-		Index ??= bulkRequestIndex ?? ClrType;
+		_bulkRequestIndex = bulkRequestIndex;
+	}
 
-		if (bulkRequestIndex is not null && (Index?.Equals(bulkRequestIndex) ?? false))
-			Index = null;
+	private void ResolveIndex(IElasticsearchClientSettings settings)
+	{
+		if (_bulkRequestIndex is not null)
+		{
+			var resolvedBulkIndex = settings.Inferrer.IndexName(_bulkRequestIndex);
+
+			string? inferredIndex;
+			if (Index is not null)
+				inferredIndex = settings.Inferrer.IndexName(Index);
+			else if (ClrType is not null)
+				inferredIndex = settings.Inferrer.TryIndexName(ClrType);
+			else
+				inferredIndex = null;
+
+			if (inferredIndex is null || inferredIndex == resolvedBulkIndex)
+				Index = null;
+			else
+				Index = inferredIndex;
+		}
+		else
+		{
+			Index ??= ClrType;
+		}
 	}
 
 	/// <inheritdoc />
-	void IStreamSerializable.Serialize(Stream stream, IElasticsearchClientSettings settings, SerializationFormatting formatting) => Serialize(stream, settings);
+	void IStreamSerializable.Serialize(Stream stream, IElasticsearchClientSettings settings, SerializationFormatting formatting)
+	{
+		ResolveIndex(settings);
+		Serialize(stream, settings);
+	}
 
 	/// <inheritdoc />
-	Task IStreamSerializable.SerializeAsync(Stream stream, IElasticsearchClientSettings settings, SerializationFormatting formatting) => SerializeAsync(stream, settings);
+	Task IStreamSerializable.SerializeAsync(Stream stream, IElasticsearchClientSettings settings, SerializationFormatting formatting)
+	{
+		ResolveIndex(settings);
+		return SerializeAsync(stream, settings);
+	}
 }