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
@@ -178,8 +178,33 @@
     if not slug:  # generate one as this is mandatory
         slug = generate_slug()
 
-    if not metadata and name and authors:
-        metadata = generate_metadata_file(name, slug, authors, temp_dir)
+    if not metadata:
+        if name and authors:
+            metadata = generate_metadata_file(name, slug, authors, temp_dir)
+        elif not archive_deposit and not partial and not deposit_id:
+            # If we meet all the following conditions:
+            # * there is not an archive-only deposit
+            # * it is not part of a multipart deposit (either create/update
+            #   or finish)
+            # * it misses either name or authors
+            raise InputError(
+                "Either a metadata file (--metadata) or both --author and "
+                "--name must be provided, unless this is an archive-only "
+                "deposit.")
+        elif name or authors:
+            # If we are generating metadata, then all mandatory metadata
+            # must be present
+            raise InputError(
+                "Either a metadata file (--metadata) or both --author and "
+                "--name must be provided.")
+        else:
+            # TODO: this is a multipart deposit, we might want to check that
+            # metadata are deposited at some point
+            pass
+    elif name or authors:
+        raise InputError(
+            "Using a metadata file (--metadata) is incompatible with "
+            "--author and --name, which are used to generate one.")
 
     if metadata_deposit:
         archive = None
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
@@ -6,6 +6,7 @@
 import contextlib
 import logging
 import os
+import re
 from unittest.mock import MagicMock
 
 from click.testing import CliRunner
@@ -121,6 +122,92 @@
 </entry>'''
 
 
+def test_metadata_validation(sample_archive, mocker, caplog, tmp_path):
+    """ from:
+    https://docs.softwareheritage.org/devel/swh-deposit/getting-started.html#single-deposit
+    """  # noqa
+    slug = generate_slug()
+    mocker.patch('swh.deposit.cli.client.generate_slug', return_value=slug)
+    mock_client = MagicMock()
+    mocker.patch(
+        'swh.deposit.cli.client._client',
+        return_value=mock_client)
+    mock_client.service_document.return_value = EXAMPLE_SERVICE_DOCUMENT
+    mock_client.deposit_create.return_value = '{"foo": "bar"}'
+
+    metadata_path = os.path.join(tmp_path, 'metadata.xml')
+    mocker.patch('swh.deposit.cli.client.tempfile.TemporaryDirectory',
+                 return_value=contextlib.nullcontext(str(tmp_path)))
+    with open(metadata_path, 'a'):
+        pass  # creates the file
+
+    runner = CliRunner()
+
+    # Test missing author
+    result = runner.invoke(cli, [
+        'upload',
+        '--url', 'mock://deposit.swh/1',
+        '--username', TEST_USER['username'],
+        '--password', TEST_USER['password'],
+        '--name', 'test-project',
+        '--archive', sample_archive['path'],
+    ])
+
+    assert result.exit_code == 1, result.output
+    assert result.output == ''
+    assert len(caplog.record_tuples) == 1
+    (_logger, level, message) = caplog.record_tuples[0]
+    assert level == logging.ERROR
+    assert ' --author ' in message
+
+    # Clear mocking state
+    caplog.clear()
+    mock_client.reset_mock()
+
+    # Test missing name
+    result = runner.invoke(cli, [
+        'upload',
+        '--url', 'mock://deposit.swh/1',
+        '--username', TEST_USER['username'],
+        '--password', TEST_USER['password'],
+        '--archive', sample_archive['path'],
+        '--author', 'Jane Doe',
+    ])
+
+    assert result.exit_code == 1, result.output
+    assert result.output == ''
+    assert len(caplog.record_tuples) == 1
+    (_logger, level, message) = caplog.record_tuples[0]
+    assert level == logging.ERROR
+    assert ' --name ' in message
+
+    # Clear mocking state
+    caplog.clear()
+    mock_client.reset_mock()
+
+    # Test both --metadata and --author
+    result = runner.invoke(cli, [
+        'upload',
+        '--url', 'mock://deposit.swh/1',
+        '--username', TEST_USER['username'],
+        '--password', TEST_USER['password'],
+        '--archive', sample_archive['path'],
+        '--metadata', metadata_path,
+        '--author', 'Jane Doe',
+    ])
+
+    assert result.exit_code == 1, result.output
+    assert result.output == ''
+    assert len(caplog.record_tuples) == 1
+    (_logger, level, message) = caplog.record_tuples[0]
+    assert level == logging.ERROR
+    assert re.search('--metadata.*is incompatible with', message)
+
+    # Clear mocking state
+    caplog.clear()
+    mock_client.reset_mock()
+
+
 def test_single_deposit_slug_generation(
         sample_archive, mocker, caplog, tmp_path, client_mock):
     """ from: