diff --git a/src/modules/events/components/CreateEventDialog.vue b/src/modules/events/components/CreateEventDialog.vue
index 7c35a48..b9ad6c1 100644
--- a/src/modules/events/components/CreateEventDialog.vue
+++ b/src/modules/events/components/CreateEventDialog.vue
@@ -598,7 +598,28 @@ const onSubmit = form.handleSubmit(
         notification_subject: formValues.notification_subject,
         notification_body: formValues.notification_body,
         promo_codes: toWirePromoCodes(promoRows.value),
-        ticket_waves: [primaryWave, ...extraWaves.value],
+        // Fiat is a per-wave opt-in in the extension, but the webapp
+        // offers ONE event-level control for it (the Card checkbox), so
+        // that checkbox governs every wave: ticking Card enables fiat on
+        // all of them, unticking disables it on all of them. Without this a
+        // wave added here refuses card payments while the event itself
+        // reads as fiat-enabled — what organisers hit on demo.
+        //
+        // Deliberately simple for now: it does mean a per-wave setting made
+        // in the LNbits admin is overwritten next time the event is saved
+        // from here. Acceptable while the webapp has no per-wave control to
+        // represent one, and better than a control that silently disagrees
+        // with what gets stored.
+        ticket_waves: [primaryWave, ...extraWaves.value].map((wave) => ({
+          ...wave,
+          allow_fiat: acceptsFiat,
+          // The event's fiat currency, unconditionally — not a fallback to
+          // whatever the wave happened to hold. Waves created before this
+          // carry the backend's "GBP" default, and a wave settling in a
+          // different currency than the event advertises is not a state the
+          // webapp can represent or an organiser can have asked for.
+          fiat_currency: formValues.fiat_currency,
+        })),
       };
 
       if (isEditMode.value) {
diff --git a/src/modules/events/components/TicketWavesEditor.vue b/src/modules/events/components/TicketWavesEditor.vue
index 189bc55..b152176 100644
--- a/src/modules/events/components/TicketWavesEditor.vue
+++ b/src/modules/events/components/TicketWavesEditor.vue
@@ -1,7 +1,6 @@
 <script setup lang="ts">
 import { computed } from "vue";
 import { Button } from "@/components/ui/button";
-import { Switch } from "@/components/ui/switch";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
 import { Plus, Trash2 } from "lucide-vue-next";
@@ -28,9 +27,10 @@ const props = defineProps<{
   knownIds?: string[];
   /** Currency of the primary wave; new rows inherit it. */
   currency?: string;
-  /** Whether the event accepts fiat, and in what. New rows inherit both:
-   *  fiat is a per-wave opt-in, so a wave created without it refuses card
-   *  payments no matter what the event-level toggle says. */
+  /** Whether the event accepts fiat, and in what. New rows inherit both so
+   *  the in-memory row is right before saving; on save the dialog applies
+   *  the event-level Card checkbox to every wave anyway, which is why
+   *  there is no per-wave switch here — it would be overwritten. */
   allowFiat?: boolean;
   fiatCurrency?: string;
   disabled?: boolean;
@@ -186,21 +186,6 @@ function isSoldOut(row: TicketWave): boolean {
         </div>
       </div>
 
-      <div
-        v-if="allowFiat"
-        class="flex items-center justify-between rounded-md bg-muted/40 px-2 py-1.5"
-      >
-        <span class="text-xs">
-          Accept card for this wave
-          <span class="text-muted-foreground">({{ row.fiat_currency }})</span>
-        </span>
-        <Switch
-          :model-value="row.allow_fiat ?? false"
-          :disabled="disabled"
-          @update:model-value="update(index, { allow_fiat: Boolean($event) })"
-        />
-      </div>
-
       <p v-if="errors[index]" class="text-xs text-destructive">
         {{ errors[index] }}
       </p>
diff --git a/src/modules/events/lib/ticketWaves.spec.ts b/src/modules/events/lib/ticketWaves.spec.ts
index 7bd7707..c827510 100644
--- a/src/modules/events/lib/ticketWaves.spec.ts
+++ b/src/modules/events/lib/ticketWaves.spec.ts
@@ -345,3 +345,48 @@ describe("newWaveRow — fiat inheritance", () => {
     expect(row.fiat_currency).toBe("EUR");
   });
 });
+
+describe("the Card checkbox governs every wave", () => {
+  // The webapp has one event-level fiat control, so on save it is applied
+  // to all waves. Pinned because getting it wrong is silent: the event
+  // reads as fiat-enabled while a wave refuses card payments, and the
+  // buyer only finds out at checkout.
+  const applyEventFiat = (
+    waves: TicketWave[],
+    acceptsFiat: boolean,
+    cur: string,
+  ) =>
+    waves.map((w) => ({ ...w, allow_fiat: acceptsFiat, fiat_currency: cur }));
+
+  const waves = [
+    wave({ id: "primary", allow_fiat: true, fiat_currency: "EUR" }),
+    wave({ id: "early", allow_fiat: false, fiat_currency: "GBP" }),
+    wave({ id: "late", allow_fiat: false, fiat_currency: "GBP" }),
+  ];
+
+  it("ticking Card enables fiat on every wave, not just the primary", () => {
+    const out = applyEventFiat(waves, true, "EUR");
+    expect(out.map((w) => w.allow_fiat)).toEqual([true, true, true]);
+    expect(out.map((w) => w.fiat_currency)).toEqual(["EUR", "EUR", "EUR"]);
+  });
+
+  it("unticking Card disables it on every wave", () => {
+    expect(
+      applyEventFiat(waves, false, "EUR").map((w) => w.allow_fiat),
+    ).toEqual([false, false, false]);
+  });
+
+  it("overwrites a stale wave fiat currency with the event's", () => {
+    // Waves created before this carry the backend's "GBP" default even on
+    // a EUR event, which is what demo showed.
+    const out = applyEventFiat(waves, true, "EUR");
+    expect(out.every((w) => w.fiat_currency === "EUR")).toBe(true);
+  });
+
+  it("leaves everything else about each wave alone", () => {
+    const [, early] = applyEventFiat(waves, true, "EUR");
+    expect(early.id).toBe("early");
+    expect(early.price_per_ticket).toBe(waves[1].price_per_ticket);
+    expect(early.amount_tickets).toBe(waves[1].amount_tickets);
+  });
+});