diff --git a/services/backup/src/http/handlers/backup.rs b/services/backup/src/http/handlers/backup.rs
--- a/services/backup/src/http/handlers/backup.rs
+++ b/services/backup/src/http/handlers/backup.rs
@@ -58,6 +58,9 @@
     Some(user_data_blob_info),
     attachments,
     siwe_backup_msg,
+    // TODO: use real values here
+    0,
+    Default::default(),
   );
 
   db_client
@@ -176,6 +179,9 @@
     Some(user_data_blob_info),
     attachments,
     existing_backup_item.siwe_backup_msg.clone(),
+    // TODO: use real values here
+    0,
+    Default::default(),
   );
 
   db_client
@@ -417,6 +423,9 @@
     user_data,
     attachments,
     siwe_backup_msg,
+    // TODO: use real values here
+    0,
+    Default::default(),
   );
 
   Ok((item, revokes))
diff --git a/shared/comm-lib/src/backup/database.rs b/shared/comm-lib/src/backup/database.rs
--- a/shared/comm-lib/src/backup/database.rs
+++ b/shared/comm-lib/src/backup/database.rs
@@ -4,6 +4,8 @@
 
 use crate::blob::types::BlobInfo;
 
+use super::BackupVersionInfo;
+
 #[cfg(feature = "blob-client")]
 use crate::blob::client::BlobServiceClient;
 #[cfg(feature = "aws")]
@@ -37,6 +39,10 @@
   pub user_data: Option<BlobInfo>,
   pub attachments: Vec<BlobInfo>,
   pub siwe_backup_msg: Option<String>,
+  #[serde(default)]
+  pub total_size: u64,
+  #[serde(default)]
+  pub version_info: BackupVersionInfo,
 }
 
 impl BackupItem {
@@ -47,6 +53,8 @@
     user_data: Option<BlobInfo>,
     attachments: Vec<BlobInfo>,
     siwe_backup_msg: Option<String>,
+    total_size: u64,
+    version_info: BackupVersionInfo,
   ) -> Self {
     BackupItem {
       user_id,
@@ -56,6 +64,8 @@
       user_data,
       attachments,
       siwe_backup_msg,
+      total_size,
+      version_info,
     }
   }
 
@@ -198,6 +208,39 @@
       user_data,
       attachments,
       siwe_backup_msg,
+      // TODO: Parse real values from DDB
+      total_size: 0,
+      version_info: Default::default(),
     })
   }
 }
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  #[test]
+  fn test_backup_item_deserialize_defaults() {
+    // BackupItem is passed between services. It might happen that one service
+    // has old implementation that doesn't include `total_size`
+    // and `version_info` fields. It should deserialize the defaults then fields. It should insert the
+    // defaults then.
+    let payload = r#"{
+      "user_id": "uid",
+      "backup_id": "bid",
+      "created":"2025-05-13T11:20:33.799712136Z",
+      "user_keys": {"blobHash":"hash1","holder":"holder1"},
+      "user_data": null,
+      "attachments": [],
+      "siwe_backup_msg": null
+    }"#;
+
+    let deserialized: BackupItem =
+      serde_json::from_str(payload).expect("failed to deserialized BackupItem");
+
+    assert_eq!(deserialized.total_size, 0u64);
+    assert_eq!(deserialized.version_info.code_version, 0u16);
+    assert_eq!(deserialized.version_info.state_version, 0u16);
+    assert_eq!(deserialized.version_info.db_version, 0u16);
+  }
+}
diff --git a/shared/comm-lib/src/backup/mod.rs b/shared/comm-lib/src/backup/mod.rs
--- a/shared/comm-lib/src/backup/mod.rs
+++ b/shared/comm-lib/src/backup/mod.rs
@@ -4,6 +4,16 @@
 /// shared database types and constants
 pub mod database;
 
+#[derive(Debug, Default, Clone, Serialize, Deserialize)]
+pub struct BackupVersionInfo {
+  /// App code version
+  pub code_version: u16,
+  /// Redux state version
+  pub state_version: u16,
+  /// SQLite DB version
+  pub db_version: u16,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct LatestBackupInfoResponse {