diff --git a/swh/deposit/cli/client.py b/swh/deposit/cli/client.py
--- a/swh/deposit/cli/client.py
+++ b/swh/deposit/cli/client.py
@@ -141,6 +141,7 @@
     """
     # retrieve user's collection
     sd_content = client.service_document()
+
     if "error" in sd_content:
         raise InputError("Service document retrieval: %s" % (sd_content["error"],))
     collection = sd_content["app:service"]["app:workspace"]["app:collection"][
diff --git a/swh/deposit/client.py b/swh/deposit/client.py
--- a/swh/deposit/client.py
+++ b/swh/deposit/client.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2017-2020  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
@@ -7,7 +7,6 @@
 
 """
 
-from abc import ABCMeta, abstractmethod
 import hashlib
 import logging
 import os
@@ -253,7 +252,7 @@
         raise ValueError(msg)
 
 
-class BaseDepositClient(BaseApiDepositClient, metaclass=ABCMeta):
+class BaseDepositClient(BaseApiDepositClient):
     """Base Deposit client to access the public api.
 
     """
@@ -265,23 +264,20 @@
         self.error_msg = error_msg
         self.empty_result = empty_result
 
-    @abstractmethod
     def compute_url(self, *args, **kwargs):
         """Compute api url endpoint to query."""
-        pass
+        raise NotImplementedError
 
-    @abstractmethod
     def compute_method(self, *args, **kwargs):
         """Http method to use on the url"""
-        pass
+        raise NotImplementedError
 
-    @abstractmethod
     def parse_result_ok(self, xml_content):
         """Given an xml result from the api endpoint, parse it and returns a
            dict.
 
         """
-        pass
+        raise NotImplementedError
 
     def compute_information(self, *args, **kwargs) -> Dict[str, Any]:
         """Compute some more information given the inputs (e.g http headers,
@@ -301,10 +297,11 @@
 
         """
         data = parse_xml(xml_content)
+        sword_error = data["sword:error"]
         return {
-            "summary": data["summary"],
-            "detail": data["detail"],
-            "sword:verboseDescription": data["sword:verboseDescription"],
+            "summary": sword_error["atom:summary"],
+            "detail": sword_error.get("detail", ""),
+            "sword:verboseDescription": sword_error.get("sword:verboseDescription", ""),
         }
 
     def do_execute(self, method, url, info):
diff --git a/swh/deposit/tests/cli/test_client.py b/swh/deposit/tests/cli/test_client.py
--- a/swh/deposit/tests/cli/test_client.py
+++ b/swh/deposit/tests/cli/test_client.py
@@ -1,4 +1,4 @@
-# Copyright (C) 2020 The Software Heritage developers
+# Copyright (C) 2020-2021 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
@@ -17,7 +17,11 @@
 from swh.deposit.api.checks import check_metadata
 from swh.deposit.cli import deposit as cli
 from swh.deposit.cli.client import InputError, _collection, _url, generate_metadata
-from swh.deposit.client import MaintenanceError, PublicApiDepositClient
+from swh.deposit.client import (
+    BaseDepositClient,
+    MaintenanceError,
+    PublicApiDepositClient,
+)
 from swh.deposit.parsers import parse_xml
 from swh.model.exceptions import ValidationError
 
@@ -915,3 +919,25 @@
     for (_, log_level, _) in caplog.record_tuples:
         # all messages are info or below messages so everything is fine
         assert log_level < logging.WARNING
+
+
+def test_cli_failure_should_be_parseable(atom_dataset, mocker):
+    summary = "Cannot load metadata"
+    verbose_description = (
+        "Cannot load metadata on swh:1:dir:0eda267e7d3c2e37b3f6a78e542b16190ac4574e, "
+        "this directory object does not exist in the archive (yet?)."
+    )
+
+    error_xml = atom_dataset["error-cli"].format(
+        summary=summary, verboseDescription=verbose_description
+    )
+
+    api_call = BaseDepositClient(url="https://somewhere.org/")
+
+    actual_error = api_call.parse_result_error(error_xml)
+
+    assert actual_error == {
+        "summary": summary,
+        "detail": "",
+        "sword:verboseDescription": verbose_description,
+    }
diff --git a/swh/deposit/tests/data/atom/error-cli.xml b/swh/deposit/tests/data/atom/error-cli.xml
new file mode 100644
--- /dev/null
+++ b/swh/deposit/tests/data/atom/error-cli.xml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<sword:error xmlns="http://www.w3.org/2005/Atom"
+             xmlns:sword="http://purl.org/net/sword/terms/">
+    <summary>{summary}</summary>
+    <sword:treatment>processing failed</sword:treatment>
+    <sword:verboseDescription>
+        {verboseDescription}
+    </sword:verboseDescription>
+</sword:error>