diff --git a/services/backup/src/Tools.h b/services/backup/src/Tools.h
--- a/services/backup/src/Tools.h
+++ b/services/backup/src/Tools.h
@@ -13,6 +13,8 @@
     const std::string &backupID,
     const std::string &resourceID = "");
 
+std::string validateAttachmentHolders(const std::string &holders);
+
 } // namespace tools
 } // namespace network
 } // namespace comm
diff --git a/services/backup/src/Tools.cpp b/services/backup/src/Tools.cpp
--- a/services/backup/src/Tools.cpp
+++ b/services/backup/src/Tools.cpp
@@ -1,10 +1,13 @@
 #include "Tools.h"
 
+#include "GlobalConstants.h"
 #include "GlobalTools.h"
 
 #include <chrono>
 #include <cstdlib>
 #include <random>
+#include <sstream>
+#include <stdexcept>
 
 namespace comm {
 namespace network {
@@ -30,6 +33,25 @@
       ID_SEPARATOR + tools::generateUUID();
 }
 
+std::string validateAttachmentHolders(const std::string &holders) {
+  std::stringstream stream(holders);
+  std::string item;
+  std::string result;
+
+  while (std::getline(stream, item, ATTACHMENT_DELIMITER)) {
+    if (item.empty()) {
+      throw std::runtime_error("empty holder detected");
+    }
+    result += item;
+    result += ATTACHMENT_DELIMITER;
+  }
+  if (result.empty()) {
+    throw std::runtime_error("parse attachment holders failed");
+  }
+
+  return result;
+}
+
 } // namespace tools
 } // namespace network
 } // namespace comm
diff --git a/services/lib/src/GlobalConstants.h b/services/lib/src/GlobalConstants.h
--- a/services/lib/src/GlobalConstants.h
+++ b/services/lib/src/GlobalConstants.h
@@ -22,7 +22,7 @@
 
 const std::string AWS_REGION = "us-east-2";
 
-const std::string ATTACHMENT_DELIMITER = ";";
+const char ATTACHMENT_DELIMITER = ';';
 
 } // namespace network
 } // namespace comm