diff --git a/swh/deposit/api/converters.py b/swh/deposit/api/converters.py
--- a/swh/deposit/api/converters.py
+++ b/swh/deposit/api/converters.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2017-2018  The Software Heritage developers
+# Copyright (C) 2017-2021  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
@@ -21,7 +21,11 @@
         'archive': [{
             'summary': "summary-string",
             'fields': [impacted-fields-list],
-        }]
+        }],
+        'loading': [
+            'error 1',
+            'error 2',
+        ],
       }
 
     Args:
@@ -52,6 +56,10 @@
     if _detail:
         msg.append("- %s%s\n" % (_detail["summary"], _str_fields(_detail)))
 
+    _detail = status_detail.get("loading")
+    if _detail:
+        msg.extend(f"- {error}\n" for error in _detail)
+
     if not msg:
         return None
     return "".join(msg)
diff --git a/swh/deposit/api/private/deposit_update_status.py b/swh/deposit/api/private/deposit_update_status.py
--- a/swh/deposit/api/private/deposit_update_status.py
+++ b/swh/deposit/api/private/deposit_update_status.py
@@ -112,4 +112,7 @@
         else:  # rejected
             deposit.status = status
 
+        if "status_detail" in data:
+            deposit.status_detail = data["status_detail"]
+
         deposit.save()
diff --git a/swh/deposit/client.py b/swh/deposit/client.py
--- a/swh/deposit/client.py
+++ b/swh/deposit/client.py
@@ -212,6 +212,7 @@
         self,
         update_status_url,
         status,
+        status_detail=None,
         revision_id=None,
         directory_id=None,
         origin_url=None,
@@ -233,6 +234,8 @@
             payload["directory_id"] = directory_id
         if origin_url:
             payload["origin_url"] = origin_url
+        if status_detail:
+            payload["status_detail"] = status_detail
 
         self.do("put", update_status_url, json=payload)
 
diff --git a/swh/deposit/tests/api/test_converters.py b/swh/deposit/tests/api/test_converters.py
--- a/swh/deposit/tests/api/test_converters.py
+++ b/swh/deposit/tests/api/test_converters.py
@@ -48,12 +48,15 @@
             {"summary": "Invalid archive", "fields": ["2"],},
             {"summary": "Unsupported archive", "fields": ["1"],},
         ],
+        "loading": ["error1", "error 2"],
     }
 
     expected_status_detail = """- Mandatory fields missing (name)
 - Invalid archive (2)
 - Unsupported archive (1)
 - At least one compatible url field. Failed (testurl)
+- error1
+- error 2
 """
 
     actual_status_detail = convert_status_detail(status_detail)
diff --git a/swh/deposit/tests/api/test_deposit_private_update_status.py b/swh/deposit/tests/api/test_deposit_private_update_status.py
--- a/swh/deposit/tests/api/test_deposit_private_update_status.py
+++ b/swh/deposit/tests/api/test_deposit_private_update_status.py
@@ -36,6 +36,7 @@
     """
     deposit = ready_deposit_verified
     expected_status = DEPOSIT_STATUS_LOAD_SUCCESS
+    status_detail = "it works!"
     origin_url = "something"
     directory_id = "42a13fc721c8716ff695d0d62fc851d641f3a12b"
     revision_id = "47dc6b4636c7f6cba0df83e3d5490bf4334d987e"
@@ -43,6 +44,7 @@
 
     full_body_info = {
         "status": DEPOSIT_STATUS_LOAD_SUCCESS,
+        "status_detail": status_detail,
         "revision_id": revision_id,
         "directory_id": directory_id,
         "snapshot_id": snapshot_id,
@@ -66,6 +68,7 @@
 
         deposit = Deposit.objects.get(pk=deposit.id)
         assert deposit.status == expected_status
+        assert deposit.status_detail == status_detail
         assert deposit.swhid == expected_swhid
         assert deposit.swhid_context == expected_swhid_context
 
diff --git a/swh/deposit/tests/loader/test_client.py b/swh/deposit/tests/loader/test_client.py
--- a/swh/deposit/tests/loader/test_client.py
+++ b/swh/deposit/tests/loader/test_client.py
@@ -213,7 +213,10 @@
 
     deposit_client = PrivateApiDepositClient(config=CLIENT_TEST_CONFIG)
     deposit_client.status_update(
-        "/update/status", DEPOSIT_STATUS_LOAD_SUCCESS, revision_id="some-revision-id",
+        "/update/status",
+        DEPOSIT_STATUS_LOAD_SUCCESS,
+        revision_id="some-revision-id",
+        status_detail="foo bar",
     )
 
     mocked_put.assert_called_once_with(
@@ -221,6 +224,7 @@
         "https://nowhere.org/update/status",
         json={
             "status": DEPOSIT_STATUS_LOAD_SUCCESS,
+            "status_detail": "foo bar",
             "revision_id": "some-revision-id",
         },
     )