stripe: per-cadence cooling-off + manage-subscription button

Bundles three related pieces that came out of the operator's first
end-to-end test of the paid flow:

1. Manage subscription button on /settings (paid users with a real
   Stripe sub — i.e. not credit-granted access). POSTs to the existing
   /api/stripe/portal endpoint; Stripe-hosted customer portal handles
   card updates, cancellation, monthly↔annual switch, invoice history.
   Replaces the stale "Paid features unlock with Paddle (D.3) or
   invite credits" hint for free users with a live link to /pricing.

2. Per-cadence cooling-off treatment:

   - **Annual £70**: 14-day free trial via
     subscription_data.trial_period_days=14. No money moves during
     the trial, so the CCR 2013 14-day refund question doesn't arise
     (nothing paid = nothing to refund). Card is still required at
     checkout so Stripe can charge on day 15.

   - **Monthly £7**: bills immediately. A 14-day trial there would
     give away ~50% of cycle one. Instead, /pricing now carries a
     required tick-box above the Subscribe buttons (subscribe stays
     disabled until checked) — by ticking, the user expressly
     consents to begin performance immediately and acknowledges that
     this extinguishes their statutory 14-day right under Reg 36
     CCR 2013. Consent collected on our own page (not via Stripe's
     account-wide consent_collection.terms_of_service) so each
     product can keep its own Terms URL as we add more.

3. T&C §6 clause 1 split into 1a (annual / trial substitute) +
   1b (monthly / Reg 36 waiver via on-page tick-box). Clause 2
   (post-cooling-off cancellation) unchanged.

Settings page shows "Free trial — N days remaining" while the
sub is in `trialing` status, falling back to "Paid subscription
active." once it transitions to active. Countdown is computed
server-side from User.stripe_trial_end_at (new column, migration
0020) populated by the subscription.created/updated webhook from
the Stripe trial_end timestamp; cleared on the trialing→active
transition and on revoke.

Drive-by: fixed a structlog kwarg-name collision on
`log.warning(..., event=event_type, ...)` in both polar_webhook.py
and stripe_billing.py — `event` is structlog's positional event
name and "got multiple values" crashed the user-not-found log
path. Renamed to `event_type=` everywhere it appeared. Caught by
the new trialing-stores-trial-end test.

Tests
- 4 new in test_stripe_billing.py covering monthly (no trial, no
  consent_collection), annual (trial, no consent), trialing stores
  trial_end, trialing→active clears trial_end.
- 1 existing test renamed + reworked for the consent split.
- Full suite: 224 passed, 5 skipped.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

alembic/versions/0020_trial_end.py

@@ -0,0 +1,31 @@
+"""stripe trial: users.stripe_trial_end_at.
+
+Revision ID: 0020
+Revises: 0019
+Create Date: 2026-05-26
+"""
+from typing import Sequence, Union
+
+import sqlalchemy as sa
+from alembic import op
+
+
+revision: str = "0020"
+down_revision: Union[str, None] = "0019"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "users",
+        sa.Column(
+            "stripe_trial_end_at",
+            sa.DateTime(timezone=True),
+            nullable=True,
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("users", "stripe_trial_end_at")

app/models.py

@@ -200,6 +200,12 @@ class User(Base):
     # back to this row.
     stripe_customer_id: Mapped[str | None] = mapped_column(String(64), nullable=True)
     stripe_subscription_id: Mapped[str | None] = mapped_column(String(64), nullable=True)
+    # Set when a subscription is in `trialing` state — drives the
+    # "Free trial — N days remaining" hint on /settings. Cleared on
+    # subscription.revoked or when status transitions out of trialing.
+    stripe_trial_end_at: Mapped[datetime | None] = mapped_column(
+        DateTime(timezone=True), nullable=True,
+    )
 
     __table_args__ = (
         UniqueConstraint("email", name="uq_users_email"),

app/routers/pages.py

@@ -154,6 +154,21 @@ async def settings_page(
         .limit(1)
     )).scalar_one_or_none()
 
+    # Trial countdown — when the Stripe subscription is in its 14-day
+    # trial, show "N days remaining" on the tier row. Computed here
+    # rather than in the template because Jinja's date arithmetic is
+    # painful, and we already have to handle MariaDB's tz-naive
+    # round-trip via _aware-style normalisation.
+    trial_days_remaining: int | None = None
+    if user.stripe_trial_end_at is not None:
+        end = user.stripe_trial_end_at
+        if end.tzinfo is None:
+            end = end.replace(tzinfo=timezone.utc)
+        delta = end - datetime.now(timezone.utc)
+        if delta.total_seconds() > 0:
+            # Round up so the last hours of the trial still read "1 day".
+            trial_days_remaining = max(1, -(-int(delta.total_seconds()) // 86400))
+
     return templates.TemplateResponse(
         request, "settings.html",
         {
@@ -163,5 +178,6 @@ async def settings_page(
             "converted_count": int(converted_count),
             "paid": paid_status(user),
             "last_email_send": last_email_send,
+            "trial_days_remaining": trial_days_remaining,
         },
     )

app/routers/polar_webhook.py

@@ -177,7 +177,7 @@ async def _handle_subscription_active(
 ) -> None:
     user = await _find_user(session, data)
     if user is None:
-        log.warning("polar.user_not_found", event=event_type,
+        log.warning("polar.user_not_found", event_type=event_type,
                     customer_id=_customer_id_from_payload(data))
         return
     await _grant_paid(session, user, data)
@@ -188,7 +188,7 @@ async def _handle_subscription_revoked(
 ) -> None:
     user = await _find_user(session, data)
     if user is None:
-        log.warning("polar.user_not_found", event=event_type,
+        log.warning("polar.user_not_found", event_type=event_type,
                     customer_id=_customer_id_from_payload(data))
         return
     await _revoke_paid(session, user)

app/routers/stripe_billing.py

@@ -120,6 +120,22 @@ async def create_checkout(
         # referral redemption flow ships.
         "allow_promotion_codes": True,
     }
+    # Per-cadence cooling-off treatment:
+    #
+    # - Annual gets a 14-day free trial. No money moves during the
+    #   trial, so the Consumer Contracts Regulations 14-day refund
+    #   question is moot (nothing paid = nothing to refund). Card is
+    #   still required at checkout so Stripe can charge on day 15.
+    #
+    # - Monthly bills immediately (a 14-day trial on a £7/month plan
+    #   would give away ~50% of cycle one). The Reg-36 waiver lives
+    #   on our own /pricing page as a required tick-box (see
+    #   pricing.html); we deliberately do NOT use Stripe's
+    #   consent_collection.terms_of_service here because that's an
+    #   account-wide setting and we want per-product control (and
+    #   per-product Terms URLs) as we grow.
+    if body.cadence == "annual":
+        create_kwargs["subscription_data"] = {"trial_period_days": 14}
     if user.stripe_customer_id:
         create_kwargs["customer"] = user.stripe_customer_id
     else:
@@ -220,17 +236,28 @@ async def _grant_paid(
     *,
     customer_id: str | None,
     subscription_id: str | None,
+    trial_end: int | None = None,
+    status: str | None = None,
 ) -> None:
     user.tier = "paid"
     if customer_id and user.stripe_customer_id != customer_id:
         user.stripe_customer_id = customer_id
     if subscription_id and user.stripe_subscription_id != subscription_id:
         user.stripe_subscription_id = subscription_id
+    # Track trial_end so the settings page can show "N days remaining".
+    # Only populated when Stripe reports the sub as trialing — once the
+    # status flips to active (paid for real), we clear the trial marker.
+    if status == "trialing" and trial_end:
+        from datetime import datetime, timezone
+        user.stripe_trial_end_at = datetime.fromtimestamp(trial_end, tz=timezone.utc)
+    elif status == "active":
+        user.stripe_trial_end_at = None
 
 
 async def _revoke_paid(user: User) -> None:
     user.tier = "free"
     user.stripe_subscription_id = None
+    user.stripe_trial_end_at = None
     # Keep stripe_customer_id so a re-subscription matches this row.
 
 
@@ -243,8 +270,12 @@ async def _handle_checkout_completed(
         customer_id=obj.get("customer"),
     )
     if user is None:
-        log.warning("stripe.user_not_found", event=event_type)
+        log.warning("stripe.user_not_found", event_type=event_type)
         return
+    # checkout.session.completed doesn't carry trial_end on the session
+    # object itself — the subscription.created event that fires right
+    # after will carry it. We grant paid here without trial info and
+    # let the subscription event fill in trial_end_at moments later.
     await _grant_paid(
         user,
         customer_id=obj.get("customer"),
@@ -260,7 +291,7 @@ async def _handle_subscription_event(
     to free if it's an end-state."""
     user = await _find_user(session, customer_id=obj.get("customer"))
     if user is None:
-        log.warning("stripe.user_not_found", event=event_type,
+        log.warning("stripe.user_not_found", event_type=event_type,
                     customer_id=obj.get("customer"))
         return
     status = obj.get("status")
@@ -273,6 +304,8 @@ async def _handle_subscription_event(
             user,
             customer_id=obj.get("customer"),
             subscription_id=obj.get("id"),
+            trial_end=obj.get("trial_end"),
+            status=status,
         )
 
 
@@ -281,7 +314,7 @@ async def _handle_subscription_deleted(
 ) -> None:
     user = await _find_user(session, customer_id=obj.get("customer"))
     if user is None:
-        log.warning("stripe.user_not_found", event=event_type,
+        log.warning("stripe.user_not_found", event_type=event_type,
                     customer_id=obj.get("customer"))
         return
     await _revoke_paid(user)

app/static/css/cassandra.css

@@ -1802,6 +1802,34 @@ a.btn-secondary:hover { color: var(--accent); border-color: var(--accent); }
   font-weight: 700;
 }
 .tier-card__cta { margin-top: 18px; }
+/* Consent block above the Subscribe buttons (paid card, logged-in
+   free user). The Subscribe buttons render disabled; ticking the box
+   is what enables them. Wording covers ToS agreement (both cadences)
+   + the Reg 36 CCR 2013 waiver (monthly only). */
+.tier-card__consent {
+  display: flex;
+  gap: 10px;
+  align-items: flex-start;
+  margin-bottom: 14px;
+  padding: 12px 14px;
+  background: var(--surface-2);
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  font-size: 12px;
+  line-height: 1.55;
+  color: var(--muted);
+  cursor: pointer;
+}
+.tier-card__consent input[type="checkbox"] {
+  flex-shrink: 0;
+  margin-top: 2px;
+  cursor: pointer;
+}
+.tier-card__consent a {
+  color: var(--accent);
+  text-decoration: underline;
+}
+.tier-card__consent strong { color: var(--text); }
 
 .tier-card__more {
   margin-top: 14px;

app/templates/pricing.html

@@ -50,8 +50,10 @@
     <div class="tier-card__tagline">Full-day news feed, hourly strategic log, follow-up chat, and AI portfolio analysis.</div>
     <div class="tier-card__price">&pound;7<span class="tier-card__price-unit"> / month</span></div>
     <div class="tier-card__price-hint">
-      Or <strong>&pound;70 / year</strong> &mdash; two months free.
+      Or <strong>&pound;70 / year</strong> &mdash; two months free, and
-      Prices in GBP, VAT where applicable.
+      starts with a <strong>14-day free trial</strong> (cancel during
+      the trial and you are not charged). Monthly plans start
+      immediately. Prices in GBP, VAT where applicable.
     </div>
     <div class="tier-card__divider"></div>
     <div class="tier-card__list-head">Everything in Free, plus</div>
@@ -74,11 +76,23 @@
       {% if paid %}
         <a class="btn-secondary btn-block" href="/settings">Manage subscription</a>
       {% elif cu and cu.user %}
+        <label class="tier-card__consent">
+          <input type="checkbox" id="tos-consent">
+          <span>
+            I agree to the <a href="/terms" target="_blank" rel="noopener">Terms of Service</a>.
+            For <strong>monthly plans</strong>, I expressly consent to begin
+            immediate access and acknowledge this waives my 14-day cancellation
+            right under Regulation 36 of the Consumer Contracts Regulations 2013.
+            (<strong>Annual plans</strong> include a 14-day free trial, so the
+            cancellation right is preserved differently &mdash; see
+            <a href="/terms" target="_blank" rel="noopener">Terms &sect;6</a>.)
+          </span>
+        </label>
         <button class="btn-primary btn-block" type="button"
-                data-stripe-checkout="monthly">Subscribe &mdash; &pound;7/month</button>
+                data-stripe-checkout="monthly" disabled>Subscribe &mdash; &pound;7/month</button>
         <button class="btn-secondary btn-block" type="button"
-                data-stripe-checkout="annual"
+                data-stripe-checkout="annual" disabled
-                style="margin-top:10px;">or &pound;70/year (two months free)</button>
+                style="margin-top:10px;">or &pound;70/year (with 14-day free trial)</button>
       {% else %}
         <a class="btn-primary btn-block" href="/login?next=/pricing">Sign in to subscribe</a>
       {% endif %}
@@ -89,10 +103,28 @@
 
 <script>
 (function () {
-  // Wire the two upgrade buttons to /api/stripe/checkout. Stripe returns
+  // Gate the Subscribe buttons on the ToS / Reg-36 consent checkbox.
-  // a hosted-checkout URL; we just redirect there. No Stripe.js needed.
+  // The buttons render with `disabled` set; toggling the checkbox is
-  document.querySelectorAll('[data-stripe-checkout]').forEach(function (btn) {
+  // what enables them. Server-side, the Reg-36 waiver applies to
+  // monthly only — but the single checkbox covers both ToS agreement
+  // (always needed) and the monthly waiver, so it's required for any
+  // subscribe path.
+  var consent = document.getElementById('tos-consent');
+  var subscribeBtns = document.querySelectorAll('[data-stripe-checkout]');
+  if (consent) {
+    consent.addEventListener('change', function () {
+      subscribeBtns.forEach(function (b) { b.disabled = !consent.checked; });
+    });
+  }
+
+  // Wire the buttons to /api/stripe/checkout. Stripe returns a
+  // hosted-checkout URL; we just redirect there. No Stripe.js needed.
+  subscribeBtns.forEach(function (btn) {
     btn.addEventListener('click', async function () {
+      if (consent && !consent.checked) {
+        alert('Please agree to the Terms of Service before subscribing.');
+        return;
+      }
       var cadence = btn.getAttribute('data-stripe-checkout');
       btn.disabled = true;
       var prev = btn.textContent;
@@ -113,7 +145,7 @@
         window.location.href = data.url;
       } catch (e) {
         alert(e.message || 'Could not start checkout. Please try again.');
-        btn.disabled = false;
+        btn.disabled = (consent && !consent.checked);
         btn.textContent = prev;
       }
     });

app/templates/settings.html

@@ -30,15 +30,66 @@
               Paid features active via credit · {{ paid.days_remaining }} day(s) remaining
               (expires {{ paid.expires_at.strftime("%Y-%m-%d") }}).
             </span>
+          {% else %}
+            {% if trial_days_remaining %}
+              <span class="settings-row__hint">
+                <strong>Free trial</strong> &mdash; {{ trial_days_remaining }}
+                day{{ '' if trial_days_remaining == 1 else 's' }} remaining.
+                Cancel before the trial ends and you won&rsquo;t be charged.
+              </span>
             {% else %}
               <span class="settings-row__hint">Paid subscription active.</span>
             {% endif %}
+            {% if user.stripe_customer_id %}
+              <button type="button" id="stripe-portal-btn"
+                      class="btn-secondary"
+                      style="margin-left:10px; padding:6px 14px; font-size:12px;">
+                Manage subscription
+              </button>
+              <div class="settings-row__hint" style="margin-top:6px;">
+                Update payment method, view invoices, switch monthly &harr; annual, or cancel any time. Opens the Stripe-hosted billing portal.
+              </div>
+            {% endif %}
+          {% endif %}
         {% else %}
-          <span class="settings-row__hint">Paid features unlock with Paddle (D.3) or invite credits.</span>
+          <span class="settings-row__hint">
+            Free tier &mdash; <a href="/pricing">upgrade for £7/month or £70/year</a>.
+          </span>
         {% endif %}
       </div>
     </div>
 
+    {% if paid and paid.active and paid.source != "credit" and user.stripe_customer_id %}
+    <script>
+    (function () {
+      var btn = document.getElementById('stripe-portal-btn');
+      if (!btn) return;
+      btn.addEventListener('click', async function () {
+        btn.disabled = true;
+        var prev = btn.textContent;
+        btn.textContent = 'Opening portal…';
+        try {
+          var r = await fetch('/api/stripe/portal', {
+            method: 'POST',
+            credentials: 'same-origin',
+          });
+          if (!r.ok) {
+            var detail = '';
+            try { detail = (await r.json()).detail || ''; } catch (e) {}
+            throw new Error('Could not open portal: ' + (detail || r.status));
+          }
+          var data = await r.json();
+          window.location.href = data.url;
+        } catch (e) {
+          alert(e.message || 'Could not open portal. Please try again.');
+          btn.disabled = false;
+          btn.textContent = prev;
+        }
+      });
+    })();
+    </script>
+    {% endif %}
+
     {# --- Import portfolio --------------------------------------------- #}
     <div class="settings-section" id="import">
       <div class="settings-section__head">Import portfolio (Trading 212 CSV)</div>

app/templates/terms.html

@@ -98,13 +98,32 @@
 <section class="public-section">
   <h2 class="public-section__head">6. Refunds</h2>
   <p>
-    <strong>14-day cooling-off (UK / EU consumers).</strong> If you buy a
+    <strong>14-day cooling-off period (UK / EU consumers).</strong>
-    paid subscription as a consumer, you have 14 days from the day of
+    The Consumer Contracts (Information, Cancellation and Additional
-    purchase to cancel and receive a full refund of that purchase, under
+    Charges) Regulations 2013 give consumers a 14-day right to cancel
-    the Consumer Contracts (Information, Cancellation and Additional
+    digital service contracts. We honour this right in different ways
-    Charges) Regulations 2013. As noted in clause 5, if you start using
+    depending on your billing cadence.
-    a paid feature inside the cancellation window you lose the right to
+  </p>
-    cancel in respect of digital content already delivered.
+  <p>
+    <strong>1a. Annual subscriptions.</strong> Every new annual
+    subscription begins with a 14-day free trial. No payment is taken
+    during the trial; cancel any time before the trial ends and you
+    are not charged. This is offered as a substitute for, and is at
+    least as generous as, the statutory 14-day refund right. After
+    the trial ends and the first payment is taken, the rules in
+    paragraph 2 below apply.
+  </p>
+  <p>
+    <strong>1b. Monthly subscriptions.</strong> Monthly subscribers
+    receive immediate access to paid features at checkout and are
+    billed on day one. Before you can start a monthly subscription
+    you must tick a required consent box on the pricing page in
+    which you (i) agree to these Terms, (ii) give express consent to
+    begin performance immediately, and (iii) acknowledge that, under
+    Regulation 36 of the Consumer Contracts Regulations 2013, doing
+    so extinguishes your statutory 14-day right to cancel in respect
+    of digital content already delivered. The rules in paragraph 2
+    below apply from the first day.
   </p>
   <p>
     <strong>Cancellation after the cooling-off window.</strong> You can

tests/test_stripe_billing.py

@@ -190,6 +190,110 @@ def test_subscription_deleted_drops_tier_to_free(tmp_path):
     assert sid is None
 
 
+def test_subscription_trialing_stores_trial_end(tmp_path):
+    """customer.subscription.created with status=trialing + trial_end
+    should grant paid AND persist the trial_end timestamp so the
+    settings page can show 'N days remaining'.
+
+    Realistic flow: checkout.session.completed fires first (linking
+    customer_id to user.id via client_reference_id), then
+    subscription.created fires moments later carrying trial_end."""
+    import datetime as _dt
+    client, factory, _ = _build_app(tmp_path)
+    # First: link the user to the Stripe customer via checkout.
+    _post_webhook(client, body={
+        "id": "evt_link",
+        "type": "checkout.session.completed",
+        "data": {"object": {
+            "client_reference_id": "1",
+            "customer": "cus_trial",
+            "subscription": "sub_trial",
+        }},
+    })
+    # Then: the subscription event carrying trial_end (12 days out).
+    trial_end_ts = int((_dt.datetime.now(_dt.timezone.utc)
+                        + _dt.timedelta(days=12)).timestamp())
+    r = _post_webhook(client, body={
+        "id": "evt_trial",
+        "type": "customer.subscription.created",
+        "data": {"object": {
+            "id": "sub_trial",
+            "customer": "cus_trial",
+            "status": "trialing",
+            "trial_end": trial_end_ts,
+        }},
+    })
+    assert r.status_code == 200, r.text
+
+    async def _check():
+        from sqlalchemy import select
+        from app.models import User
+        async with factory() as session:
+            u = (await session.execute(
+                select(User).where(User.id == 1)
+            )).scalar_one()
+            return u.tier, u.stripe_trial_end_at
+
+    tier, end = asyncio.run(_check())
+    assert tier == "paid", "trial users must have paid features"
+    assert end is not None
+    # Stored value should match the trial_end we sent (within a second).
+    expected = _dt.datetime.fromtimestamp(trial_end_ts, tz=_dt.timezone.utc)
+    if end.tzinfo is None:
+        end = end.replace(tzinfo=_dt.timezone.utc)
+    assert abs((end - expected).total_seconds()) < 2
+
+
+def test_subscription_active_clears_trial_end(tmp_path):
+    """When the subscription transitions trialing -> active (day 15),
+    the trial_end marker should be cleared so settings stops showing
+    'trial — N days remaining'."""
+    import datetime as _dt
+    client, factory, _ = _build_app(tmp_path)
+    # Link the customer first via checkout, then plant a trial state.
+    _post_webhook(client, body={
+        "id": "evt_link2",
+        "type": "checkout.session.completed",
+        "data": {"object": {
+            "client_reference_id": "1",
+            "customer": "cus_t",
+            "subscription": "sub_t",
+        }},
+    })
+    trial_end_ts = int((_dt.datetime.now(_dt.timezone.utc)
+                        + _dt.timedelta(days=12)).timestamp())
+    _post_webhook(client, body={
+        "id": "evt_t1",
+        "type": "customer.subscription.created",
+        "data": {"object": {
+            "id": "sub_t", "customer": "cus_t",
+            "status": "trialing", "trial_end": trial_end_ts,
+        }},
+    })
+    # Now transition to active.
+    _post_webhook(client, body={
+        "id": "evt_t2",
+        "type": "customer.subscription.updated",
+        "data": {"object": {
+            "id": "sub_t", "customer": "cus_t",
+            "status": "active",
+        }},
+    })
+
+    async def _check():
+        from sqlalchemy import select
+        from app.models import User
+        async with factory() as session:
+            u = (await session.execute(
+                select(User).where(User.id == 1)
+            )).scalar_one()
+            return u.tier, u.stripe_trial_end_at
+
+    tier, end = asyncio.run(_check())
+    assert tier == "paid"
+    assert end is None, "trial_end_at must be cleared once active"
+
+
 def test_subscription_active_grants_paid(tmp_path):
     """customer.subscription.updated with status=active should also
     grant paid — covers the case where checkout.session.completed
@@ -282,9 +386,9 @@ def test_unknown_event_is_acked(tmp_path):
 # --- /api/stripe/checkout (with Stripe SDK mocked) ------------------------
 
 
-def test_checkout_endpoint_creates_session_and_returns_url(tmp_path):
+def _fake_checkout_client(asserter):
-    client, _, session_cookie = _build_app(tmp_path)
+    """Build a fake Stripe client whose checkout.sessions.create calls
-    # Mock the Stripe SDK call so no real HTTP goes out.
+    the supplied asserter on the params dict and returns a stub URL."""
     fake_session = SimpleNamespace(
         id="cs_test_123", url="https://checkout.stripe.com/test",
     )
@@ -292,10 +396,7 @@ def test_checkout_endpoint_creates_session_and_returns_url(tmp_path):
     class _FakeSessions:
         @staticmethod
         def create(params):  # noqa: ANN001
-            assert params["mode"] == "subscription"
+            asserter(params)
-            assert params["line_items"][0]["price"] == _PRICE_MONTHLY
-            assert params["client_reference_id"] == "1"
-            assert params["customer_email"] == "buyer@x"
             return fake_session
 
     class _FakeCheckout:
@@ -304,8 +405,28 @@ def test_checkout_endpoint_creates_session_and_returns_url(tmp_path):
     class _FakeClient:
         checkout = _FakeCheckout()
 
+    return _FakeClient()
+
+
+def test_checkout_monthly_has_no_trial_and_no_stripe_consent(tmp_path):
+    """Monthly checkout must NOT carry a free trial (£7 × 14 days would
+    halve cycle-1 revenue) AND must NOT use Stripe's account-wide
+    consent_collection — the Reg-36 waiver is collected on /pricing
+    so each product can use its own Terms URL."""
+    client, _, session_cookie = _build_app(tmp_path)
+
+    def asserter(params):
+        assert params["mode"] == "subscription"
+        assert params["line_items"][0]["price"] == _PRICE_MONTHLY
+        assert params["client_reference_id"] == "1"
+        assert params["customer_email"] == "buyer@x"
+        assert "subscription_data" not in params, "no trial on monthly"
+        assert "consent_collection" not in params, (
+            "consent is collected on /pricing, not via Stripe's account-wide setting"
+        )
+
     with patch("app.routers.stripe_billing._stripe_client",
-               return_value=_FakeClient()):
+               return_value=_fake_checkout_client(asserter)):
         r = client.post(
             "/api/stripe/checkout",
             json={"cadence": "monthly"},
@@ -315,6 +436,28 @@ def test_checkout_endpoint_creates_session_and_returns_url(tmp_path):
     assert r.json()["url"] == "https://checkout.stripe.com/test"
 
 
+def test_checkout_annual_uses_trial_not_consent_collection(tmp_path):
+    """Annual checkout gets the 14-day free trial (substitutes for the
+    statutory cooling-off right; no money moves during the trial)."""
+    client, _, session_cookie = _build_app(tmp_path)
+
+    def asserter(params):
+        assert params["mode"] == "subscription"
+        assert params["line_items"][0]["price"] == _PRICE_ANNUAL
+        assert params["subscription_data"]["trial_period_days"] == 14
+        assert "consent_collection" not in params, "annual relies on trial, not consent"
+
+    with patch("app.routers.stripe_billing._stripe_client",
+               return_value=_fake_checkout_client(asserter)):
+        r = client.post(
+            "/api/stripe/checkout",
+            json={"cadence": "annual"},
+            cookies={"cassandra_session": session_cookie},
+        )
+    assert r.status_code == 200, r.text
+    assert r.json()["url"] == "https://checkout.stripe.com/test"
+
+
 def test_checkout_endpoint_requires_login(tmp_path):
     client, _, _ = _build_app(tmp_path)
     r = client.post("/api/stripe/checkout", json={"cadence": "monthly"})