diff --git a/limacharlie/commands/mailsec.py b/limacharlie/commands/mailsec.py
index 31e4eb91..9b463ffb 100644
--- a/limacharlie/commands/mailsec.py
+++ b/limacharlie/commands/mailsec.py
@@ -149,13 +149,13 @@
 _EXPLAIN_CAMPAIGN_ACTION = """\
 Sweep an action across every member of a campaign. Requires mailsec.act.
 
-PREVIEWS BY DEFAULT. --confirm <campaign_id> is what turns the preview
-into an execution, which is the right default for an operation whose
-blast radius is every mailbox that received the attack.
+PREVIEWS BY DEFAULT. Copy the preview's member-bound `confirm` token into
+--confirm to execute exactly the reviewed member set. A campaign id is not
+a confirmation token and is refused by the server.
 
 Examples:
   limacharlie mailsec campaign action ec7e273b-... --action quarantine_message
-  limacharlie mailsec campaign action ec7e273b-... --action quarantine_message --confirm ec7e273b-...
+  limacharlie mailsec campaign action ec7e273b-... --action quarantine_message --confirm 3c514e...
 """
 
 _EXPLAIN_SENDER_GET = """\
@@ -666,7 +666,7 @@ def campaign_get(ctx, campaign_id) -> None:
 @click.argument("campaign_id")
 @click.option("--action", "action_name", required=True, help="The typed action to sweep.")
 @click.option("--confirm", default=None,
-              help="Pass the campaign id to EXECUTE. Omit to preview — previewing is the default.")
+              help="Pass the member-bound token returned by the preview to EXECUTE. Omit to preview.")
 @click.option("--reason", default=None, help="Recorded on every resulting audit row.")
 @pass_context
 def campaign_action(ctx, campaign_id, action_name, confirm, reason) -> None:
@@ -677,7 +677,7 @@ def campaign_action(ctx, campaign_id, action_name, confirm, reason) -> None:
 
     \b
     Example:
-      limacharlie mailsec campaign action ec7e273b-... --action quarantine_message --confirm ec7e273b-...
+      limacharlie mailsec campaign action ec7e273b-... --action quarantine_message --confirm 3c514e...
     """
     ms = _get_mailsec(ctx)
     _output(ctx, ms.act_on_campaign(campaign_id, action_name, confirm=confirm, reason=reason))
diff --git a/limacharlie/sdk/mailsec.py b/limacharlie/sdk/mailsec.py
index 9349b5b4..63733e61 100644
--- a/limacharlie/sdk/mailsec.py
+++ b/limacharlie/sdk/mailsec.py
@@ -384,7 +384,8 @@ def act_on_campaign(
         Args:
             campaign_id: The campaign to sweep.
             action: The typed action, as for :meth:`act_on_message`.
-            confirm: Pass the campaign id to execute. Omit to preview.
+            confirm: Pass the member-bound token returned by the preview to
+                execute. Omit to preview.
             reason: Recorded on every resulting audit row.
             actor: Ignored if supplied — the gateway stamps the acting
                 identity from the authenticated claims, so an audit trail's
diff --git a/tests/unit/test_cli_mailsec.py b/tests/unit/test_cli_mailsec.py
index 516cf3c9..e5d2dca6 100644
--- a/tests/unit/test_cli_mailsec.py
+++ b/tests/unit/test_cli_mailsec.py
@@ -23,6 +23,27 @@ def invoke_connection(*args: str):
         return result, mailsec
 
 
+def invoke_campaign_action(*args: str):
+    with (
+        patch("limacharlie.commands.mailsec.Client"),
+        patch("limacharlie.commands.mailsec.Organization"),
+        patch("limacharlie.commands.mailsec.Mailsec") as mailsec_cls,
+    ):
+        mailsec = MagicMock()
+        mailsec.act_on_campaign.return_value = {"preview": False, "succeeded": 1}
+        mailsec_cls.return_value = mailsec
+        result = CliRunner().invoke(
+            cli,
+            [
+                "--oid", "11111111-2222-3333-4444-555555555555",
+                "--output", "json",
+                "mailsec", "campaign", "action", "campaign-1",
+                *args,
+            ],
+        )
+        return result, mailsec
+
+
 def test_connection_diagnostic_is_read_only_by_default():
     result, mailsec = invoke_connection("workspace")
     assert result.exit_code == 0, result.output
@@ -33,3 +54,25 @@ def test_include_watch_reaches_the_public_sdk_call():
     result, mailsec = invoke_connection("workspace", "--include-watch")
     assert result.exit_code == 0, result.output
     mailsec.test_connection.assert_called_once_with("workspace", include_watch=True)
+
+
+def test_campaign_action_help_requires_the_preview_token():
+    result = CliRunner().invoke(cli, ["mailsec", "campaign", "action", "--help"])
+    assert result.exit_code == 0, result.output
+    assert "member-bound token returned by the preview" in result.output
+    assert "Pass the campaign id" not in result.output
+
+
+def test_campaign_action_forwards_the_preview_token_unchanged():
+    result, mailsec = invoke_campaign_action(
+        "--action", "quarantine_message",
+        "--confirm", "member-bound-token",
+        "--reason", "reviewed current set",
+    )
+    assert result.exit_code == 0, result.output
+    mailsec.act_on_campaign.assert_called_once_with(
+        "campaign-1",
+        "quarantine_message",
+        confirm="member-bound-token",
+        reason="reviewed current set",
+    )
diff --git a/tests/unit/test_sdk_mailsec.py b/tests/unit/test_sdk_mailsec.py
index 065b94fd..50aa7c7a 100644
--- a/tests/unit/test_sdk_mailsec.py
+++ b/tests/unit/test_sdk_mailsec.py
@@ -159,9 +159,9 @@ def test_campaign_action_previews_without_confirm(self, ms, mock_org):
         assert "confirm" not in body
 
     def test_campaign_action_confirm_is_forwarded(self, ms, mock_org):
-        ms.act_on_campaign("cmp-1", "quarantine_message", confirm="cmp-1")
+        ms.act_on_campaign("cmp-1", "quarantine_message", confirm="member-bound-token")
         _, body = _post_call(mock_org)
-        assert body["confirm"] == "cmp-1"
+        assert body["confirm"] == "member-bound-token"
 
 
 class TestConnectionDiagnostics: