diff --git a/docs/user/netservices/NetServicesDefs.dox b/docs/user/netservices/NetServicesDefs.dox
index f6ea6a2541..767822ba59 100644
--- a/docs/user/netservices/NetServicesDefs.dox
+++ b/docs/user/netservices/NetServicesDefs.dox
@@ -212,15 +212,31 @@ namespace Network {
 
 /*!
 	\fn BNetworkRequestError::BNetworkRequestError(const char *origin, ErrorType type,
-		status_t errorCode=B_OK)
+		status_t errorCode, const BString& customMessage = BString())
 	\brief Create a new network request error.
 
 	\param origin A string representing where this error occured. It is advised
 		to initialize it to \c __PRETTY_FUNCTION__ by default.
 	\param type The error type that describes what the issue was that prevented the completion of
 		the request.
-	\param errorCode Optional underlying system error. See the \ref BNetworkRequestError::ErrorType
+	\param errorCode The underlying system error. See the \ref BNetworkRequestError::ErrorType
 		documentation on which error types expect a system error.
+	\param customMessage Optional custom message describing the reason or cause for the error.
+
+	\since Haiku R1
+*/
+
+
+/*!
+	\fn BNetworkRequestError::BNetworkRequestError(const char *origin, ErrorType type,
+		const BString& customMessage = BString())
+	\brief Create a new network request error.
+
+	\param origin A string representing where this error occured. It is advised
+		to initialize it to \c __PRETTY_FUNCTION__ by default.
+	\param type The error type that describes what the issue was that prevented the completion of
+		the request.
+	\param customMessage Optional custom message describing the reason or cause for the error.
 
 	\since Haiku R1
 */
@@ -248,6 +264,16 @@ namespace Network {
 */
 
 
+/*!
+	\fn const char* BNetworkRequestError::CustomMessage() const noexcept
+	\brief Get the custom error message.
+
+	\return Get the custom error message. This may be an empty string if it was not set.
+
+	\since Haiku R1
+*/
+
+
 /*!
 	\fn BString encode_to_base64(const BString& string)
 	\brief Utility function that encodes a \a string to base64 and returns the result.
diff --git a/headers/private/netservices2/NetServicesDefs.h b/headers/private/netservices2/NetServicesDefs.h
index 62202cb712..8e3f2f4854 100644
--- a/headers/private/netservices2/NetServicesDefs.h
+++ b/headers/private/netservices2/NetServicesDefs.h
@@ -61,7 +61,9 @@ public:
 	};
 
 							BNetworkRequestError(const char* origin, ErrorType type,
-								status_t errorCode = B_OK);
+								status_t errorCode, const BString& customMessage = BString());
+							BNetworkRequestError(const char* origin, ErrorType type,
+								const BString& customMessage = BString());
 
 	virtual	const char*		Message() const noexcept override;
 	virtual	BString			DebugMessage() const override;
@@ -69,9 +71,12 @@ public:
 			ErrorType		Type() const noexcept;
 			status_t		ErrorCode() const noexcept;
 
+	const	char*			CustomMessage() const noexcept;
+
 private:
 			ErrorType		fErrorType;
 			status_t		fErrorCode = B_OK;
+			BString			fCustomMessage;
 };
 
 
diff --git a/src/kits/network/libnetservices2/HttpBuffer.cpp b/src/kits/network/libnetservices2/HttpBuffer.cpp
index c0cb8123c8..f737082dbc 100644
--- a/src/kits/network/libnetservices2/HttpBuffer.cpp
+++ b/src/kits/network/libnetservices2/HttpBuffer.cpp
@@ -204,8 +204,10 @@ HttpBuffer::Data() const noexcept
 HttpBuffer&
 HttpBuffer::operator<<(const std::string_view& data)
 {
-	if (data.size() > (fBuffer.capacity() - fBuffer.size()))
-		throw BNetworkRequestError(__PRETTY_FUNCTION__, BNetworkRequestError::ProtocolError);
+	if (data.size() > (fBuffer.capacity() - fBuffer.size())) {
+		throw BNetworkRequestError(__PRETTY_FUNCTION__, BNetworkRequestError::ProtocolError,
+			"No capacity left in buffer to append data.");
+	}
 
 	for (const auto& character: data)
 		fBuffer.push_back(static_cast<const std::byte>(character));
diff --git a/src/kits/network/libnetservices2/HttpSession.cpp b/src/kits/network/libnetservices2/HttpSession.cpp
index 1181f710de..511df6233d 100644
--- a/src/kits/network/libnetservices2/HttpSession.cpp
+++ b/src/kits/network/libnetservices2/HttpSession.cpp
@@ -954,13 +954,18 @@ BHttpSession::Request::ReceiveResult()
 				auto locationField = fFields.FindField("Location");
 				if (locationField == fFields.end()) {
 					throw BNetworkRequestError(__PRETTY_FUNCTION__,
-						BNetworkRequestError::ProtocolError);
+						BNetworkRequestError::ProtocolError,
+						"Redirect; the Location field must be present and cannot be found");
 				}
 				auto locationString = BString((*locationField).Value().data(),
 					(*locationField).Value().size());
-				auto redirect = BHttpSession::Redirect{BUrl(fRequest.Url(), locationString), redirectToGet};
-				if (!redirect.url.IsValid())
-					throw BNetworkRequestError(__PRETTY_FUNCTION__, BNetworkRequestError::ProtocolError);
+				auto redirect =
+					BHttpSession::Redirect{BUrl(fRequest.Url(), locationString), redirectToGet};
+				if (!redirect.url.IsValid()) {
+					throw BNetworkRequestError(__PRETTY_FUNCTION__,
+						BNetworkRequestError::ProtocolError,
+						"Redirect; invalid URL in the Location field");
+				}
 
 				// Notify of redirect
 				SendMessage(UrlEvent::HttpRedirect, [&locationString](BMessage& msg) {
@@ -1009,12 +1014,16 @@ BHttpSession::Request::ReceiveResult()
 						fNoContent = true;
 					fParser.SetContentLength(bodyBytesTotal);
 				} catch (const std::logic_error& e) {
-					throw BNetworkRequestError(__PRETTY_FUNCTION__, BNetworkRequestError::ProtocolError);
+					throw BNetworkRequestError(__PRETTY_FUNCTION__,
+						BNetworkRequestError::ProtocolError,
+						"Cannot parse Content-Length field value (logic_error)");
 				}
 			}
 
-			if (bodyBytesTotal  == std::nullopt)
-				throw BNetworkRequestError(__PRETTY_FUNCTION__, BNetworkRequestError::ProtocolError);
+			if (bodyBytesTotal  == std::nullopt) {
+				throw BNetworkRequestError(__PRETTY_FUNCTION__,
+					BNetworkRequestError::ProtocolError, "Expected Content-Length field");
+			}
 		}
 
 		// Move headers to the result and inform listener
diff --git a/src/kits/network/libnetservices2/NetServicesMisc.cpp b/src/kits/network/libnetservices2/NetServicesMisc.cpp
index b6e626eb92..2d29655a7f 100644
--- a/src/kits/network/libnetservices2/NetServicesMisc.cpp
+++ b/src/kits/network/libnetservices2/NetServicesMisc.cpp
@@ -98,8 +98,17 @@ BInvalidUrl::Url() const
 // #pragma mark -- BNetworkRequestError
 
 
-BNetworkRequestError::BNetworkRequestError(const char* origin, ErrorType type, status_t errorCode)
-	: BError(origin), fErrorType(type), fErrorCode(errorCode)
+BNetworkRequestError::BNetworkRequestError(const char* origin, ErrorType type, status_t errorCode,
+		const BString& customMessage)
+	: BError(origin), fErrorType(type), fErrorCode(errorCode), fCustomMessage(customMessage)
+{
+
+}
+
+
+BNetworkRequestError::BNetworkRequestError(const char* origin, ErrorType type,
+		const BString& customMessage)
+	: BError(origin), fErrorType(type), fCustomMessage(customMessage)
 {
 
 }
@@ -134,6 +143,9 @@ BNetworkRequestError::DebugMessage() const
 		debugMessage << "\n\tUnderlying System Error: " << fErrorCode << " ("
 			<< strerror(fErrorCode) << ")";
 	}
+	if (fCustomMessage.Length() > 0) {
+		debugMessage << "\n\tAdditional Info: " << fCustomMessage;
+	}
 	return debugMessage;
 }
 
@@ -152,6 +164,13 @@ BNetworkRequestError::ErrorCode() const noexcept
 }
 
 
+const char*
+BNetworkRequestError::CustomMessage() const noexcept
+{
+	return fCustomMessage.String();
+}
+
+
 // #pragma mark -- Public functions