diff --git a/server/api/ballot_manifest.py b/server/api/ballot_manifest.py
index c0a4dc580..4067b794e 100644
--- a/server/api/ballot_manifest.py
+++ b/server/api/ballot_manifest.py
@@ -1,4 +1,4 @@
-from typing import Optional
+from typing import BinaryIO, Optional
 import uuid
 import logging
 from datetime import datetime
@@ -12,6 +12,7 @@
 from ..models import *  # pylint: disable=wildcard-import
 from ..auth import restrict_access, UserType, get_loggedin_user, get_support_user
 from ..worker.tasks import (
+    UserError,
     background_task,
     create_background_task,
 )
@@ -57,6 +58,8 @@ class CountingGroup(str, enum.Enum):
 NUMBER_OF_BALLOTS = "Number of Ballots"
 CVR = "CVR"
 
+BATCH_INVENTORY_WORKSHEET_UPLOADED_ERROR = 'You have uploaded a Batch Inventory Worksheet. Please upload a ballot manifest file exported from Step 4: "Download Audit Files".'
+
 
 def all_manifests_uploaded(contest: Contest):
     return all(
@@ -143,6 +146,7 @@ def process() -> None:
             )
 
         manifest_file = retrieve_file(jurisdiction.manifest_file.storage_path)
+        validate_is_not_batch_inventory_worksheet(manifest_file)
         manifest_csv = parse_csv(manifest_file, columns)
 
         counting_group_allowlist = [item.value for item in CountingGroup]
@@ -229,6 +233,17 @@ def process() -> None:
         session.commit()
 
 
+def is_batch_inventory_worksheet(first_line: bytes) -> bool:
+    return first_line.decode("utf-8").strip() == "Batch Inventory Worksheet"
+
+
+def validate_is_not_batch_inventory_worksheet(file: BinaryIO):
+    first_line = file.readline()
+    file.seek(0)
+    if is_batch_inventory_worksheet(first_line):
+        raise UserError(BATCH_INVENTORY_WORKSHEET_UPLOADED_ERROR)
+
+
 def save_ballot_manifest_file(
     storage_path: str, file_name: str, jurisdiction: Jurisdiction
 ):
diff --git a/server/tests/api/test_ballot_manifest.py b/server/tests/api/test_ballot_manifest.py
index 94c58ebd4..f1b2d7176 100644
--- a/server/tests/api/test_ballot_manifest.py
+++ b/server/tests/api/test_ballot_manifest.py
@@ -155,6 +155,41 @@ def test_ballot_manifest_upload_missing_file_path(
     }
 
 
+def test_ballot_manifest_upload_batch_inventory_worksheet(
+    client: FlaskClient, election_id: str, jurisdiction_ids: List[str]
+):
+    set_logged_in_user(
+        client, UserType.JURISDICTION_ADMIN, default_ja_email(election_id)
+    )
+
+    rv = upload_ballot_manifest(
+        client,
+        io.BytesIO(b"Batch Inventory Worksheet \r\n"),
+        election_id,
+        jurisdiction_ids[0],
+    )
+    assert_ok(rv)
+
+    rv = client.get(
+        f"/api/election/{election_id}/jurisdiction/{jurisdiction_ids[0]}/ballot-manifest"
+    )
+    compare_json(
+        json.loads(rv.data),
+        {
+            "file": {
+                "name": asserts_startswith("manifest"),
+                "uploadedAt": assert_is_date,
+            },
+            "processing": {
+                "status": ProcessingStatus.ERRORED,
+                "startedAt": assert_is_date,
+                "completedAt": assert_is_date,
+                "error": 'You have uploaded a Batch Inventory Worksheet. Please upload a ballot manifest file exported from Step 4: "Download Audit Files".',
+            },
+        },
+    )
+
+
 def test_ballot_manifest_upload_bad_csv(
     client: FlaskClient, election_id: str, jurisdiction_ids: List[str]
 ):