diff --git a/services/backup/src/Reactors/server/CreateNewBackupReactor.cpp b/services/backup/src/Reactors/server/CreateNewBackupReactor.cpp
--- a/services/backup/src/Reactors/server/CreateNewBackupReactor.cpp
+++ b/services/backup/src/Reactors/server/CreateNewBackupReactor.cpp
@@ -9,8 +9,11 @@
 namespace reactor {
 
 std::string CreateNewBackupReactor::generateBackupID() {
-  // mock
-  return generateRandomString();
+  if (this->deviceID.empty()) {
+    throw std::runtime_error(
+        "trying to generate a backup ID with an empty device ID");
+  }
+  return this->deviceID + std::to_string(getCurrentTimestamp());
 }
 
 std::unique_ptr<ServerBidiReactorStatus> CreateNewBackupReactor::handleRequest(
@@ -52,8 +55,13 @@
       this->dataHash = request.newcompactionhash();
       this->state = State::DATA_CHUNKS;
 
-      // TODO confirm - holder may be a backup id
       this->backupID = this->generateBackupID();
+      if (database::DatabaseManager::getInstance().findBackupItem(
+              this->userID, this->backupID) != nullptr) {
+        throw std::runtime_error(
+            "Backup with id [" + this->backupID + "] for user [" +
+            this->userID + "] already exists, creation aborted");
+      }
       response->set_backupid(this->backupID);
       this->holder = this->backupID;
       this->putReactor = std::make_shared<reactor::BlobPutClientReactor>(