diff --git a/swh/deposit/api/common.py b/swh/deposit/api/common.py
--- a/swh/deposit/api/common.py
+++ b/swh/deposit/api/common.py
@@ -19,13 +19,12 @@
 
 from swh.model import hashutil
 from swh.scheduler.utils import create_oneshot_task_dict
-from swh.deposit.utils import origin_url_from
 
 from ..config import (
     SWHDefaultConfig, EDIT_SE_IRI, EM_IRI, CONT_FILE_IRI,
     ARCHIVE_KEY, METADATA_KEY, RAW_METADATA_KEY, STATE_IRI,
     DEPOSIT_STATUS_DEPOSITED, DEPOSIT_STATUS_PARTIAL,
-    DEPOSIT_STATUS_VERIFIED, PRIVATE_CHECK_DEPOSIT,
+    PRIVATE_CHECK_DEPOSIT,
     DEPOSIT_STATUS_LOAD_SUCCESS, ARCHIVE_TYPE, METADATA_TYPE
 )
 from ..errors import (
@@ -184,14 +183,6 @@
                     'check-deposit', deposit_check_url=check_url)
                 check_task_id = scheduler.create_tasks([task])[0]['id']
                 deposit.check_task_id = check_task_id
-            elif (deposit.status == DEPOSIT_STATUS_VERIFIED and
-                  not deposit.load_task_id):
-
-                url = origin_url_from(deposit)
-                task = create_oneshot_task_dict(
-                    'load-deposit', url=url, deposit_id=deposit.id)
-                load_task_id = scheduler.create_task([task])[0]['id']
-                deposit.load_task_id = load_task_id
 
         deposit.save()
 
diff --git a/swh/deposit/api/private/__init__.py b/swh/deposit/api/private/__init__.py
--- a/swh/deposit/api/private/__init__.py
+++ b/swh/deposit/api/private/__init__.py
@@ -5,7 +5,7 @@
 
 from swh.deposit import utils
 
-from ...config import METADATA_TYPE
+from ...config import METADATA_TYPE, SWHDefaultConfig
 from ...models import DepositRequest, Deposit
 
 from rest_framework.permissions import AllowAny
@@ -56,7 +56,7 @@
         return utils.merge(*metadata)
 
 
-class SWHPrivateAPIView(SWHAPIView):
+class SWHPrivateAPIView(SWHDefaultConfig, SWHAPIView):
     """Mixin intended as private api (so no authentication) based API view
        (for the private ones).
 
diff --git a/swh/deposit/api/private/deposit_check.py b/swh/deposit/api/private/deposit_check.py
--- a/swh/deposit/api/private/deposit_check.py
+++ b/swh/deposit/api/private/deposit_check.py
@@ -8,8 +8,12 @@
 import tarfile
 import zipfile
 
+from itertools import chain
+from shutil import get_unpack_formats
+
 from rest_framework import status
 
+from swh.scheduler.utils import create_oneshot_task_dict
 
 from . import DepositReadMixin, SWHPrivateAPIView
 from ..common import SWHGetDepositAPI
@@ -33,6 +37,11 @@
     r'.*\.(%s)$' % '|'.join(ARCHIVE_EXTENSIONS))
 
 
+def known_archive_format(filename):
+    return any(filename.endswith(t) for t in
+               chain(*(x[1] for x in get_unpack_formats())))
+
+
 class SWHChecksDeposit(SWHPrivateAPIView, SWHGetDepositAPI, DepositReadMixin):
     """Dedicated class to read a deposit's raw archives content.
 
@@ -92,6 +101,10 @@
 
         """
         archive_path = archive_request.archive.path
+
+        if not known_archive_format(archive_path):
+            return False, MANDATORY_ARCHIVE_UNSUPPORTED
+
         try:
             if zipfile.is_zipfile(archive_path):
                 with zipfile.ZipFile(archive_path) as f:
@@ -203,6 +216,12 @@
             response = {
                 'status': deposit.status,
             }
+            if not deposit.load_task_id and self.config['checks']:
+                url = deposit.origin_url
+                task = create_oneshot_task_dict(
+                    'load-deposit', url=url, deposit_id=deposit.id)
+                load_task_id = self.scheduler.create_tasks([task])[0]['id']
+                deposit.load_task_id = load_task_id
 
         deposit.save()
 
diff --git a/swh/deposit/api/private/deposit_read.py b/swh/deposit/api/private/deposit_read.py
--- a/swh/deposit/api/private/deposit_read.py
+++ b/swh/deposit/api/private/deposit_read.py
@@ -15,7 +15,6 @@
 from swh.core import tarball
 from swh.model import identifiers
 from swh.deposit.utils import normalize_date
-from swh.deposit import utils
 
 from . import DepositReadMixin, SWHPrivateAPIView
 from ...config import SWH_PERSON, ARCHIVE_TYPE
@@ -177,7 +176,7 @@
         data = {
             'origin': {
                 'type': 'deposit',
-                'url': utils.origin_url_from(deposit),
+                'url': deposit.origin_url,
             }
         }
 
diff --git a/swh/deposit/client/__init__.py b/swh/deposit/client/__init__.py
--- a/swh/deposit/client/__init__.py
+++ b/swh/deposit/client/__init__.py
@@ -14,6 +14,7 @@
 import logging
 
 from abc import ABCMeta, abstractmethod
+from urllib.parse import urljoin
 
 from swh.core.config import SWHConfig
 
@@ -82,7 +83,7 @@
             self.config = config
 
         self._client = _client
-        self.base_url = self.config['url']
+        self.base_url = self.config['url'].lstrip('/')
         auth = self.config['auth']
         if auth == {}:
             self.auth = None
@@ -109,7 +110,7 @@
         if self.auth:
             kwargs['auth'] = self.auth
 
-        full_url = '%s%s' % (self.base_url.rstrip('/'), url)
+        full_url = urljoin(self.base_url, url.lstrip('/'))
         return method_fn(full_url, *args, **kwargs)
 
 
diff --git a/swh/deposit/models.py b/swh/deposit/models.py
--- a/swh/deposit/models.py
+++ b/swh/deposit/models.py
@@ -151,6 +151,11 @@
             d['status_detail'] = self.status_detail
         return str(d)
 
+    @property
+    def origin_url(self):
+        return '%s/%s' % (self.client.provider_url.rstrip('/'),
+                          self.external_id)
+
 
 def client_directory_path(instance, filename):
     """Callable to upload archive in MEDIA_ROOT/user_<id>/<filename>
diff --git a/swh/deposit/tests/api/test_deposit_private_check.py b/swh/deposit/tests/api/test_deposit_private_check.py
--- a/swh/deposit/tests/api/test_deposit_private_check.py
+++ b/swh/deposit/tests/api/test_deposit_private_check.py
@@ -237,7 +237,7 @@
 
     # now we create an archive holding the first created archive
     invalid_archive = create_archive_with_archive(
-        root_path, 'invalid.tar.gz', archive)
+        root_path, 'invalid.tgz', archive)
 
     # we deposit it
     response = client.post(
diff --git a/swh/deposit/tests/test_utils.py b/swh/deposit/tests/test_utils.py
--- a/swh/deposit/tests/test_utils.py
+++ b/swh/deposit/tests/test_utils.py
@@ -8,43 +8,6 @@
 from unittest.mock import patch
 
 from swh.deposit import utils
-from swh.deposit.models import Deposit, DepositClient
-
-
-def test_origin_url_from():
-    """With correctly setup-ed deposit, all is fine
-
-    """
-    for provider_url, external_id in (
-            ('http://somewhere.org', 'uuid'),
-            ('http://overthejungle.org', 'diuu'),
-    ):
-        deposit = Deposit(
-            client=DepositClient(provider_url=provider_url),
-            external_id=external_id
-        )
-
-        actual_origin_url = utils.origin_url_from(deposit)
-
-        assert actual_origin_url == '%s/%s' % (
-            provider_url.rstrip('/'), external_id)
-
-
-def test_origin_url_from_ko():
-    """Badly configured deposit should raise
-
-    """
-    for provider_url, external_id in (
-            (None, 'uuid'),
-            ('http://overthejungle.org', None),
-    ):
-        deposit = Deposit(
-            client=DepositClient(provider_url=provider_url),
-            external_id=None
-        )
-
-        with pytest.raises(AssertionError):
-            utils.origin_url_from(deposit)
 
 
 def test_merge():
diff --git a/swh/deposit/utils.py b/swh/deposit/utils.py
--- a/swh/deposit/utils.py
+++ b/swh/deposit/utils.py
@@ -10,31 +10,6 @@
 from swh.model.identifiers import normalize_timestamp
 
 
-def origin_url_from(deposit):
-    """Given a deposit instance, return the associated origin url.
-
-    This expects a deposit and the associated client to be correctly
-    configured.
-
-    Args:
-        deposit (Deposit): The deposit from which derives the origin url
-
-    Raises:
-        AssertionError if:
-        - the client's provider_url field is not configured.
-        - the deposit's external_id field is not configured.
-
-    Returns
-       The associated origin url
-
-    """
-    external_id = deposit.external_id
-    assert external_id is not None
-    base_url = deposit.client.provider_url
-    assert base_url is not None
-    return '%s/%s' % (base_url.rstrip('/'), external_id)
-
-
 def merge(*dicts):
     """Given an iterator of dicts, merge them losing no information.