diff --git a/infrastructure/terraform/components/notifyai/lambda.tf b/infrastructure/terraform/components/notifyai/lambda.tf
index b25e78d..b403a86 100644
--- a/infrastructure/terraform/components/notifyai/lambda.tf
+++ b/infrastructure/terraform/components/notifyai/lambda.tf
@@ -108,6 +108,7 @@ resource "aws_lambda_function" "bedrock-messager" {
       env_logging_s3_key_prefix = local.s3_lambda_logging_key
       env_guardrail_arn         = aws_bedrock_guardrail.notifai-bedrock-guardrail.guardrail_arn
       env_guardrail_version     = "DRAFT"
+      env_logging_s3_account_id = var.aws_account_id
     }
   }
 }
diff --git a/src/backend/bedrock-prompt-messager/core/config.py b/src/backend/bedrock-prompt-messager/core/config.py
index 98dde26..16845c4 100644
--- a/src/backend/bedrock-prompt-messager/core/config.py
+++ b/src/backend/bedrock-prompt-messager/core/config.py
@@ -12,3 +12,4 @@ def __init__(self):
         self.logging_s3_key_prefix = os.environ.get("env_logging_s3_key_prefix")
         self.guardrail = os.environ.get("env_guardrail_arn")
         self.guardrail_version = os.environ.get("env_guardrail_version")
+        self.logging_s3_account_id = os.environ.get("env_logging_s3_account_id")
diff --git a/src/backend/bedrock-prompt-messager/services/bedrock_service.py b/src/backend/bedrock-prompt-messager/services/bedrock_service.py
index 412f25c..7b6ce3c 100644
--- a/src/backend/bedrock-prompt-messager/services/bedrock_service.py
+++ b/src/backend/bedrock-prompt-messager/services/bedrock_service.py
@@ -135,7 +135,7 @@ def _get_admail_tool_config(self):
     def log_prompt_details_to_s3(
         self, promptinput, promptoutput, guardrail_assessment, filename
     ):
-        if not self.config.logging_s3_bucket or not self.config.logging_s3_key_prefix:
+        if not self.config.logging_s3_bucket or not self.config.logging_s3_key_prefix or not self.config.logging_s3_account_id:
             print(constants.ERROR_S3_LOGGING_NOT_CONFIGURED)
             return
 
@@ -164,6 +164,7 @@ def log_prompt_details_to_s3(
                 Key=s3_key,
                 Body=json.dumps(log_data, indent=4),
                 ContentType="application/json",
+                ExpectedBucketOwner=self.config.logging_s3_account_id,
             )
         except Exception as e:
             print(f"Error logging to S3: {e}")
diff --git a/src/backend/bedrock-prompt-messager/tests/conftest.py b/src/backend/bedrock-prompt-messager/tests/conftest.py
index a55da7c..cec5217 100644
--- a/src/backend/bedrock-prompt-messager/tests/conftest.py
+++ b/src/backend/bedrock-prompt-messager/tests/conftest.py
@@ -12,3 +12,4 @@ def set_env_vars(monkeypatch):
     monkeypatch.setenv("env_logging_s3_key_prefix", "logs/")
     monkeypatch.setenv("env_guardrail_arn", "test-arn")
     monkeypatch.setenv("env_guardrail_version", "1")
+    monkeypatch.setenv("env_logging_s3_account_id", "123456789012")