diff --git a/src/dsp_tools/commands/ingest_xmlupload/bulk_ingest_client.py b/src/dsp_tools/commands/ingest_xmlupload/bulk_ingest_client.py
index 77f164feff..199cec7a2a 100644
--- a/src/dsp_tools/commands/ingest_xmlupload/bulk_ingest_client.py
+++ b/src/dsp_tools/commands/ingest_xmlupload/bulk_ingest_client.py
@@ -4,6 +4,7 @@
 from pathlib import Path
 from typing import Iterator
 
+import regex
 from loguru import logger
 from requests import JSONDecodeError
 from requests import RequestException
@@ -58,16 +59,17 @@ def upload_file(
         filepath: Path,
     ) -> UploadFailure | None:
         """Uploads a file to the ingest server."""
-        url = f"{self.dsp_ingest_url}/projects/{self.shortcode}/bulk-ingest/ingest/{urllib.parse.quote(str(filepath))}"
-        headers = {"Content-Type": "application/octet-stream"}
-        timeout = 600
-        err_msg = f"Failed to upload '{filepath}' to '{url}'."
         try:
             with open(self.imgdir / filepath, "rb") as binary_io:
                 content = binary_io.read()
         except OSError as e:
+            err_msg = f"Cannot bulk-ingest {filepath}, because the file could not be opened/read: {e.strerror}"
             logger.error(err_msg)
-            return UploadFailure(filepath, f"File could not be opened/read: {e.strerror}")
+            return UploadFailure(filepath, err_msg)
+        url = self._build_url_for_bulk_ingest_ingest_route(filepath)
+        headers = {"Content-Type": "application/octet-stream"}
+        timeout = 600
+        err_msg = f"Failed to upload '{filepath}' to '{url}'."
         try:
             logger.debug(f"REQUEST: POST to {url}, timeout: {timeout}, headers: {headers}")
             res = self.session.post(
@@ -84,9 +86,23 @@ def upload_file(
             logger.error(err_msg)
             reason = f"Response {res.status_code}: {res.text}" if res.text else f"Response {res.status_code}"
             return UploadFailure(filepath, reason)
-
         return None
 
+    def _build_url_for_bulk_ingest_ingest_route(self, filepath: Path) -> str:
+        """
+        Remove the leading slash of absolute filepaths,
+        because the /project/<shortcode>/bulk-ingest/ingest route only accepts relative paths.
+        The leading slash has to be added again in the "ingest-xmlupload" step, when applying the ingest ID.
+
+        Args:
+            filepath: filepath
+
+        Returns:
+            url
+        """
+        quoted = regex.sub(r"^\/", "", urllib.parse.quote(str(filepath)))
+        return f"{self.dsp_ingest_url}/projects/{self.shortcode}/bulk-ingest/ingest/{quoted}"
+
     def trigger_ingest_process(self) -> None:
         """Start the ingest process on the server."""
         url = f"{self.dsp_ingest_url}/projects/{self.shortcode}/bulk-ingest"
diff --git a/test/unittests/commands/ingest_xmlupload/test_bulk_ingest_client.py b/test/unittests/commands/ingest_xmlupload/test_bulk_ingest_client.py
index 6b856873d3..3b3621c584 100644
--- a/test/unittests/commands/ingest_xmlupload/test_bulk_ingest_client.py
+++ b/test/unittests/commands/ingest_xmlupload/test_bulk_ingest_client.py
@@ -28,6 +28,7 @@ def tmp_file(tmp_path: Path) -> Path:
 
 def _make_url(file: Path) -> str:
     filename = urllib.parse.quote(str(file))
+    filename = filename[1:] if filename.startswith("/") else filename
     return f"{DSP_INGEST_URL}/projects/{SHORTCODE}/bulk-ingest/ingest/{filename}"
 
 
@@ -51,7 +52,7 @@ def test_upload_file_with_inexisting_file(ingest_client: BulkIngestClient) -> No
     failure_detail = ingest_client.upload_file(Path("inexisting.xml"))
     assert failure_detail
     assert failure_detail.filepath == Path("inexisting.xml")
-    assert failure_detail.reason == "File could not be opened/read: No such file or directory"
+    assert re.search(r"the file could not be opened/read", failure_detail.reason)
 
 
 def test_upload_file_failure_upon_request_exception(
@@ -87,6 +88,21 @@ def test_upload_file_failure_upon_server_error_with_response_text(
     assert failure_detail.reason == "Response 500: response text"
 
 
+@pytest.mark.parametrize(
+    ("filepath", "url_suffix"),
+    [
+        (Path("Côté gauche/Süd.png"), "C%C3%B4t%C3%A9%20gauche/S%C3%BCd.png"),
+        (Path("/absolute/path/to/file.txt"), "absolute/path/to/file.txt"),
+    ],
+)
+def test_build_url_for_bulk_ingest_ingest_route(
+    ingest_client: BulkIngestClient, filepath: Path, url_suffix: str
+) -> None:
+    res = ingest_client._build_url_for_bulk_ingest_ingest_route(filepath)
+    common_part = f"{DSP_INGEST_URL}/projects/{SHORTCODE}/bulk-ingest/ingest/"
+    assert res == f"{common_part}{url_suffix}"
+
+
 def test_trigger_if_success(ingest_client: BulkIngestClient, requests_mock: Mocker) -> None:
     url = f"{DSP_INGEST_URL}/projects/{SHORTCODE}/bulk-ingest"
     requests_mock.post(url, status_code=202, text=json.dumps({"id": SHORTCODE}))