diff --git a/skills/managed-pentesting-with-strix/SKILL.md b/skills/managed-pentesting-with-strix/SKILL.md
index 261d6a55..4195111a 100644
--- a/skills/managed-pentesting-with-strix/SKILL.md
+++ b/skills/managed-pentesting-with-strix/SKILL.md
@@ -71,6 +71,8 @@ strix cloud billing topup --credits 20 --yes   # --yes skips the confirmation pr
 strix cloud billing topup --credits 20 --no-pay   # print the 402 challenge without paying
 ```
 
+Card payments need a payer-side Stripe payment method. Pass it with `--payment-method pm_...` or set `MPPX_STRIPE_PAYMENT_METHOD`, together with the payer key in `MPPX_STRIPE_SECRET_KEY`. A funded `mppx` account (`npx mppx account create`) works for stablecoin payments without those variables.
+
 If no wallet is available, print the challenge with `--no-pay` and ask the user to top up in the dashboard instead.
 
 Automatic top-ups (admin): `strix cloud billing auto-topup` shows the setting. Enable it with:
diff --git a/strix/interface/cloud/runner.py b/strix/interface/cloud/runner.py
index 7c400609..7f7300c2 100644
--- a/strix/interface/cloud/runner.py
+++ b/strix/interface/cloud/runner.py
@@ -8,6 +8,7 @@ from __future__ import annotations
 
 import argparse
 import json
+import os
 import re
 import shutil
 import subprocess
@@ -219,6 +220,15 @@ def _build_parser(group: str, verb_label: str, cmd: Cmd) -> argparse.ArgumentPar
             action="store_true",
             help="Print the payment challenge instead of paying it.",
         )
+        parser.add_argument(
+            "--payment-method",
+            default=None,
+            metavar="PM_ID",
+            help=(
+                "Stripe payment method for the card payment, for example pm_card_visa "
+                "in test mode. Defaults to MPPX_STRIPE_PAYMENT_METHOD."
+            ),
+        )
     return parser
 
 
@@ -362,8 +372,17 @@ def _topup(
 
     url = f"{http.app_url()}/api/v1/billing/topup"
     auth_header = f"Authorization: Bearer {http.api_token(token)}"
-    result = subprocess.run(  # noqa: S603
-        [npx, "--yes", "mppx", url, "-J", json.dumps(body), "-H", auth_header],
-        check=False,
+    command = [npx, "--yes", "mppx", url, "-J", json.dumps(body), "-H", auth_header]
+    payment_method = getattr(args, "payment_method", None) or os.environ.get(
+        "MPPX_STRIPE_PAYMENT_METHOD"
     )
+    if payment_method:
+        command += ["-M", f"paymentMethod={payment_method}"]
+    elif not os.environ.get("MPPX_ACCOUNT") and not os.environ.get("MPPX_STRIPE_SECRET_KEY"):
+        console.print(
+            "[dim]Tip: card payments need a wallet. Pass --payment-method, or set "
+            "MPPX_STRIPE_SECRET_KEY and MPPX_STRIPE_PAYMENT_METHOD, or create an "
+            "mppx account first with `npx mppx account create`.[/]"
+        )
+    result = subprocess.run(command, check=False)  # noqa: S603
     return http.EXIT_OK if result.returncode == 0 else http.EXIT_PAYMENT
diff --git a/tests/test_cloud_cli.py b/tests/test_cloud_cli.py
index 08501c35..820a30b5 100644
--- a/tests/test_cloud_cli.py
+++ b/tests/test_cloud_cli.py
@@ -4,6 +4,8 @@ from __future__ import annotations
 
 import io
 import json
+import shutil
+import subprocess
 import webbrowser
 from typing import TYPE_CHECKING, Any
 
@@ -300,6 +302,28 @@ def test_topup_success_without_payment(monkeypatch: pytest.MonkeyPatch, capsys:
     assert json.loads(capsys.readouterr().out) == receipt
 
 
+def test_topup_passes_payment_method_to_wallet(monkeypatch: pytest.MonkeyPatch) -> None:
+    challenge = {"payment_requirements": [{"amount": 500}]}
+    monkeypatch.setattr(
+        http, "request", lambda *_a, **_k: FakeResponse(status_code=402, payload=challenge)
+    )
+    monkeypatch.setattr(http, "api_token", lambda *_a, **_k: "tok")
+    monkeypatch.setattr(shutil, "which", lambda _name: "/usr/bin/npx")
+    commands: list[list[str]] = []
+
+    def fake_run(command: list[str], **_kwargs: Any) -> Any:
+        commands.append(command)
+        return type("Result", (), {"returncode": 0})()
+
+    monkeypatch.setattr(subprocess, "run", fake_run)
+    code = cloud.run_cloud(
+        ["billing", "topup", "--credits", "5", "--yes", "--payment-method", "pm_card_visa"]
+    )
+    assert code == 0
+    assert "-M" in commands[0]
+    assert "paymentMethod=pm_card_visa" in commands[0]
+
+
 def test_render_json_mode_when_not_a_tty() -> None:
     assert render.json_mode(flag=True) is True
     # Under pytest, stdout is captured and is not a terminal.